diff --git a/xo-alloc2/include/xo/alloc2/Collector.hpp b/xo-alloc2/include/xo/alloc2/Collector.hpp
new file mode 100644
index 00000000..45c7fdb5
--- /dev/null
+++ b/xo-alloc2/include/xo/alloc2/Collector.hpp
@@ -0,0 +1,13 @@
+/** @file Collector.hpp
+ *
+ *  @author Roland Conybeare, Dec 2025
+ **/
+
+#pragma once
+
+#include "gc/ACollector.hpp"
+#include "gc/ICollector_Any.hpp"
+#include "gc/ICollector_Xfer.hpp"
+#include "gc/RCollector.hpp"
+
+/* end Collector.hpp */
diff --git a/xo-gc/include/xo/gc/GCObject.hpp b/xo-alloc2/include/xo/alloc2/GCObject.hpp
similarity index 89%
rename from xo-gc/include/xo/gc/GCObject.hpp
rename to xo-alloc2/include/xo/alloc2/GCObject.hpp
index c40ffb3a..b7758ace 100644
--- a/xo-gc/include/xo/gc/GCObject.hpp
+++ b/xo-alloc2/include/xo/alloc2/GCObject.hpp
@@ -13,10 +13,10 @@
 
 #pragma once
 
-#include "detail/AGCObject.hpp"
-#include "detail/IGCObject_Any.hpp"
-#include "detail/IGCObject_Xfer.hpp"
-#include "detail/RGCObject.hpp"
+#include "gc/AGCObject.hpp"
+#include "gc/IGCObject_Any.hpp"
+#include "gc/IGCObject_Xfer.hpp"
+#include "gc/RGCObject.hpp"
 
 namespace xo {
     namespace mm {
diff --git a/xo-alloc2/include/xo/alloc2/alloc/AAllocator.hpp b/xo-alloc2/include/xo/alloc2/alloc/AAllocator.hpp
index ecc52862..74c1c6ba 100644
--- a/xo-alloc2/include/xo/alloc2/alloc/AAllocator.hpp
+++ b/xo-alloc2/include/xo/alloc2/alloc/AAllocator.hpp
@@ -31,7 +31,8 @@ namespace xo {
          *  Implementations of AAllocator will downcast to a
          *  to some specific representation.
          **/
-        struct AAllocator {
+        class AAllocator {
+        public:
             /** @defgroup mm-allocator-type-traits allocator type traits **/
             ///@{
             /** memory size report **/
diff --git a/xo-gc/include/xo/gc/detail/ACollector.hpp b/xo-alloc2/include/xo/alloc2/gc/ACollector.hpp
similarity index 97%
rename from xo-gc/include/xo/gc/detail/ACollector.hpp
rename to xo-alloc2/include/xo/alloc2/gc/ACollector.hpp
index bd19fe51..1dfca96a 100644
--- a/xo-gc/include/xo/gc/detail/ACollector.hpp
+++ b/xo-alloc2/include/xo/alloc2/gc/ACollector.hpp
@@ -11,8 +11,8 @@
 #include <xo/facet/typeseq.hpp>
 #include <xo/facet/obj.hpp>
 
-#include "generation.hpp"
-#include "role.hpp"
+#include <xo/alloc2/generation.hpp>
+#include <xo/alloc2/role.hpp>
 
 #include <cstdint>
 #include <cstddef>
diff --git a/xo-gc/include/xo/gc/detail/AGCObject.hpp b/xo-alloc2/include/xo/alloc2/gc/AGCObject.hpp
similarity index 97%
rename from xo-gc/include/xo/gc/detail/AGCObject.hpp
rename to xo-alloc2/include/xo/alloc2/gc/AGCObject.hpp
index 6f6e7b92..87fc6664 100644
--- a/xo-gc/include/xo/gc/detail/AGCObject.hpp
+++ b/xo-alloc2/include/xo/alloc2/gc/AGCObject.hpp
@@ -15,7 +15,7 @@
 
 // includes (via {facet_includes})
 #include <xo/alloc2/Allocator.hpp>
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 #include <cstdint>
 #include <cstddef>
 #include <xo/facet/obj.hpp>
@@ -31,7 +31,7 @@ using Copaque = const void *;
 using Opaque = void *;
 
 /**
-GC hooks for collector-aware data
+   GC hooks for collector-aware data
 **/
 class AGCObject {
 public:
diff --git a/xo-gc/include/xo/gc/detail/ICollector_Any.hpp b/xo-alloc2/include/xo/alloc2/gc/ICollector_Any.hpp
similarity index 100%
rename from xo-gc/include/xo/gc/detail/ICollector_Any.hpp
rename to xo-alloc2/include/xo/alloc2/gc/ICollector_Any.hpp
diff --git a/xo-gc/include/xo/gc/detail/ICollector_Xfer.hpp b/xo-alloc2/include/xo/alloc2/gc/ICollector_Xfer.hpp
similarity index 100%
rename from xo-gc/include/xo/gc/detail/ICollector_Xfer.hpp
rename to xo-alloc2/include/xo/alloc2/gc/ICollector_Xfer.hpp
diff --git a/xo-gc/include/xo/gc/detail/IGCObject_Any.hpp b/xo-alloc2/include/xo/alloc2/gc/IGCObject_Any.hpp
similarity index 100%
rename from xo-gc/include/xo/gc/detail/IGCObject_Any.hpp
rename to xo-alloc2/include/xo/alloc2/gc/IGCObject_Any.hpp
diff --git a/xo-gc/include/xo/gc/detail/IGCObject_Xfer.hpp b/xo-alloc2/include/xo/alloc2/gc/IGCObject_Xfer.hpp
similarity index 98%
rename from xo-gc/include/xo/gc/detail/IGCObject_Xfer.hpp
rename to xo-alloc2/include/xo/alloc2/gc/IGCObject_Xfer.hpp
index 7f094ab7..12010edf 100644
--- a/xo-gc/include/xo/gc/detail/IGCObject_Xfer.hpp
+++ b/xo-alloc2/include/xo/alloc2/gc/IGCObject_Xfer.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include <xo/alloc2/Allocator.hpp>
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 #include <cstdint>
 #include <cstddef>
 
diff --git a/xo-gc/include/xo/gc/detail/RCollector.hpp b/xo-alloc2/include/xo/alloc2/gc/RCollector.hpp
similarity index 100%
rename from xo-gc/include/xo/gc/detail/RCollector.hpp
rename to xo-alloc2/include/xo/alloc2/gc/RCollector.hpp
diff --git a/xo-gc/include/xo/gc/detail/RGCObject.hpp b/xo-alloc2/include/xo/alloc2/gc/RGCObject.hpp
similarity index 100%
rename from xo-gc/include/xo/gc/detail/RGCObject.hpp
rename to xo-alloc2/include/xo/alloc2/gc/RGCObject.hpp
diff --git a/xo-gc/include/xo/gc/generation.hpp b/xo-alloc2/include/xo/alloc2/generation.hpp
similarity index 100%
rename from xo-gc/include/xo/gc/generation.hpp
rename to xo-alloc2/include/xo/alloc2/generation.hpp
diff --git a/xo-gc/include/xo/gc/role.hpp b/xo-alloc2/include/xo/alloc2/role.hpp
similarity index 100%
rename from xo-gc/include/xo/gc/role.hpp
rename to xo-alloc2/include/xo/alloc2/role.hpp
diff --git a/xo-expression2/include/xo/expression2/DConstant.hpp b/xo-expression2/include/xo/expression2/DConstant.hpp
index 0c57f924..2c8b4a96 100644
--- a/xo-expression2/include/xo/expression2/DConstant.hpp
+++ b/xo-expression2/include/xo/expression2/DConstant.hpp
@@ -8,8 +8,8 @@
 #include "Expression.hpp"
 #include "TypeRef.hpp"
 #include "exprtype.hpp"
-#include <xo/gc/Collector.hpp>
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/Collector.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/reflect/TaggedPtr.hpp>
 
 namespace xo {
diff --git a/xo-expression2/include/xo/expression2/DIfElseExpr.hpp b/xo-expression2/include/xo/expression2/DIfElseExpr.hpp
index 3b7b07e2..0cf71332 100644
--- a/xo-expression2/include/xo/expression2/DIfElseExpr.hpp
+++ b/xo-expression2/include/xo/expression2/DIfElseExpr.hpp
@@ -8,7 +8,7 @@
 #include "Expression.hpp"
 #include "TypeRef.hpp"
 #include "exprtype.hpp"
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 #include <xo/alloc2/Allocator.hpp>
 //#include <vector>
 #include <string>
diff --git a/xo-expression2/include/xo/expression2/DUniqueString.hpp b/xo-expression2/include/xo/expression2/DUniqueString.hpp
index 30655b45..e43624bd 100644
--- a/xo-expression2/include/xo/expression2/DUniqueString.hpp
+++ b/xo-expression2/include/xo/expression2/DUniqueString.hpp
@@ -1,5 +1,5 @@
 /** @file DUniqueString.hpp
-*
+ *
  *  @author Roland Conybeare, Jan 2026
  **/
 
@@ -69,12 +69,7 @@ namespace xo {
             /** compare unique strings: return n with {n<0, n=0, n>0}
              *  when @p lhs lexicographically {before, at, after} @p rhs
              **/
-            static int compare(const DUniqueString & lhs, const DUniqueString & rhs) {
-                if (&lhs == &rhs)
-                    return 0;
-
-                return DString::compare(*(lhs._text()), *(rhs._text()));
-            }
+            static int compare(const DUniqueString & lhs, const DUniqueString & rhs);
 
             std::size_t hash() const noexcept { return _text()->hash(); }
             operator std::string_view() const noexcept { return std::string_view(*_text()); }
@@ -124,14 +119,6 @@ namespace xo {
             ///@}
 
             friend class StringTable;
-
-        private:
-#ifdef NOPE
-            /** interned string.  Note stringtable memory distinct from gc memory,
-             *  so gc will not (and should not) traverse this pointer.
-             **/
-            const DString * text_ = nullptr;
-#endif
         };
 
         /* since unique: just compare addresses */
diff --git a/xo-expression2/include/xo/expression2/define/IGCObject_DDefineExpr.hpp b/xo-expression2/include/xo/expression2/define/IGCObject_DDefineExpr.hpp
index 216dd18b..321ce4e9 100644
--- a/xo-expression2/include/xo/expression2/define/IGCObject_DDefineExpr.hpp
+++ b/xo-expression2/include/xo/expression2/define/IGCObject_DDefineExpr.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DDefineExpr.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-expression2/include/xo/expression2/detail/IGCObject_DApplyExpr.hpp b/xo-expression2/include/xo/expression2/detail/IGCObject_DApplyExpr.hpp
index 10b08c10..f0bf15ff 100644
--- a/xo-expression2/include/xo/expression2/detail/IGCObject_DApplyExpr.hpp
+++ b/xo-expression2/include/xo/expression2/detail/IGCObject_DApplyExpr.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DApplyExpr.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-expression2/include/xo/expression2/detail/IGCObject_DConstant.hpp b/xo-expression2/include/xo/expression2/detail/IGCObject_DConstant.hpp
index 871f9c91..da593190 100644
--- a/xo-expression2/include/xo/expression2/detail/IGCObject_DConstant.hpp
+++ b/xo-expression2/include/xo/expression2/detail/IGCObject_DConstant.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DConstant.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-expression2/include/xo/expression2/detail/IGCObject_DIfElseExpr.hpp b/xo-expression2/include/xo/expression2/detail/IGCObject_DIfElseExpr.hpp
index 6a47d9b8..20cea34f 100644
--- a/xo-expression2/include/xo/expression2/detail/IGCObject_DIfElseExpr.hpp
+++ b/xo-expression2/include/xo/expression2/detail/IGCObject_DIfElseExpr.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DIfElseExpr.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-expression2/include/xo/expression2/detail/IGCObject_DLambdaExpr.hpp b/xo-expression2/include/xo/expression2/detail/IGCObject_DLambdaExpr.hpp
index 7d1ba5b0..2f4e72e0 100644
--- a/xo-expression2/include/xo/expression2/detail/IGCObject_DLambdaExpr.hpp
+++ b/xo-expression2/include/xo/expression2/detail/IGCObject_DLambdaExpr.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DLambdaExpr.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-expression2/include/xo/expression2/detail/IGCObject_DSequenceExpr.hpp b/xo-expression2/include/xo/expression2/detail/IGCObject_DSequenceExpr.hpp
index 1f6b8deb..51009ecd 100644
--- a/xo-expression2/include/xo/expression2/detail/IGCObject_DSequenceExpr.hpp
+++ b/xo-expression2/include/xo/expression2/detail/IGCObject_DSequenceExpr.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DSequenceExpr.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-expression2/include/xo/expression2/detail/IGCObject_DUniqueString.hpp b/xo-expression2/include/xo/expression2/detail/IGCObject_DUniqueString.hpp
index 398e3eed..9968d6da 100644
--- a/xo-expression2/include/xo/expression2/detail/IGCObject_DUniqueString.hpp
+++ b/xo-expression2/include/xo/expression2/detail/IGCObject_DUniqueString.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DUniqueString.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-expression2/include/xo/expression2/detail/IGCObject_DVarRef.hpp b/xo-expression2/include/xo/expression2/detail/IGCObject_DVarRef.hpp
index e991ebb8..487e2832 100644
--- a/xo-expression2/include/xo/expression2/detail/IGCObject_DVarRef.hpp
+++ b/xo-expression2/include/xo/expression2/detail/IGCObject_DVarRef.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DVarRef.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-expression2/include/xo/expression2/detail/IGCObject_DVariable.hpp b/xo-expression2/include/xo/expression2/detail/IGCObject_DVariable.hpp
index 242f335f..4728746f 100644
--- a/xo-expression2/include/xo/expression2/detail/IGCObject_DVariable.hpp
+++ b/xo-expression2/include/xo/expression2/detail/IGCObject_DVariable.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DVariable.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-expression2/include/xo/expression2/expression2_register_facets.hpp b/xo-expression2/include/xo/expression2/expression2_register_facets.hpp
index 95feeea5..1a559c72 100644
--- a/xo-expression2/include/xo/expression2/expression2_register_facets.hpp
+++ b/xo-expression2/include/xo/expression2/expression2_register_facets.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 
 namespace xo {
     namespace scm {
diff --git a/xo-expression2/include/xo/expression2/expression2_register_types.hpp b/xo-expression2/include/xo/expression2/expression2_register_types.hpp
index 6c7cc959..58105eed 100644
--- a/xo-expression2/include/xo/expression2/expression2_register_types.hpp
+++ b/xo-expression2/include/xo/expression2/expression2_register_types.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 
 namespace xo {
     namespace scm {
diff --git a/xo-expression2/include/xo/expression2/symtab/IGCObject_DGlobalSymtab.hpp b/xo-expression2/include/xo/expression2/symtab/IGCObject_DGlobalSymtab.hpp
index 92149015..f136b513 100644
--- a/xo-expression2/include/xo/expression2/symtab/IGCObject_DGlobalSymtab.hpp
+++ b/xo-expression2/include/xo/expression2/symtab/IGCObject_DGlobalSymtab.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DGlobalSymtab.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-expression2/include/xo/expression2/symtab/IGCObject_DLocalSymtab.hpp b/xo-expression2/include/xo/expression2/symtab/IGCObject_DLocalSymtab.hpp
index 94b9e279..cc770261 100644
--- a/xo-expression2/include/xo/expression2/symtab/IGCObject_DLocalSymtab.hpp
+++ b/xo-expression2/include/xo/expression2/symtab/IGCObject_DLocalSymtab.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DLocalSymtab.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-expression2/src/expression2/DDefineExpr.cpp b/xo-expression2/src/expression2/DDefineExpr.cpp
index aee6ccf9..aa1ea105 100644
--- a/xo-expression2/src/expression2/DDefineExpr.cpp
+++ b/xo-expression2/src/expression2/DDefineExpr.cpp
@@ -5,7 +5,7 @@
 
 #include "DDefineExpr.hpp"
 #include "Variable.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/gc/PolyForwarderUtil.hpp>
 #include <xo/printable2/Printable.hpp>
 #include <xo/facet/FacetRegistry.hpp>
diff --git a/xo-expression2/src/expression2/DGlobalSymtab.cpp b/xo-expression2/src/expression2/DGlobalSymtab.cpp
index 38809a38..95db6b26 100644
--- a/xo-expression2/src/expression2/DGlobalSymtab.cpp
+++ b/xo-expression2/src/expression2/DGlobalSymtab.cpp
@@ -8,7 +8,7 @@
 #include <xo/expression2/Expression.hpp>
 #include <xo/expression2/Variable.hpp>
 #include <xo/object2/Array.hpp>
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/facet/FacetRegistry.hpp>
 #include <xo/indentlog/scope.hpp>
 
diff --git a/xo-expression2/src/expression2/DIfElseExpr.cpp b/xo-expression2/src/expression2/DIfElseExpr.cpp
index 6a0b053c..649a2482 100644
--- a/xo-expression2/src/expression2/DIfElseExpr.cpp
+++ b/xo-expression2/src/expression2/DIfElseExpr.cpp
@@ -5,7 +5,7 @@
 
 #include "DIfElseExpr.hpp"
 #include "detail/IExpression_DIfElseExpr.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/printable2/Printable.hpp>
 #include <xo/facet/FacetRegistry.hpp>
 #include <xo/reflectutil/typeseq.hpp>
diff --git a/xo-expression2/src/expression2/DSequenceExpr.cpp b/xo-expression2/src/expression2/DSequenceExpr.cpp
index 22b097fb..fdc73b8e 100644
--- a/xo-expression2/src/expression2/DSequenceExpr.cpp
+++ b/xo-expression2/src/expression2/DSequenceExpr.cpp
@@ -7,7 +7,7 @@
 #include "detail/IExpression_DSequenceExpr.hpp"
 #include <xo/object2/array/IGCObject_DArray.hpp>
 #include <xo/object2/array/IPrintable_DArray.hpp>
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include <xo/printable2/Printable.hpp>
 #include <xo/facet/FacetRegistry.hpp>
diff --git a/xo-expression2/src/expression2/DUniqueString.cpp b/xo-expression2/src/expression2/DUniqueString.cpp
index c0fa26db..98a7b33c 100644
--- a/xo-expression2/src/expression2/DUniqueString.cpp
+++ b/xo-expression2/src/expression2/DUniqueString.cpp
@@ -4,6 +4,7 @@
  **/
 
 #include "DUniqueString.hpp"
+#include "DString.hpp"
 #include <xo/arena/padding.hpp>
 #include <xo/indentlog/scope.hpp>
 #include <cstring>
@@ -13,6 +14,15 @@ namespace xo {
     using xo::facet::typeseq;
 
     namespace scm {
+        int
+        DUniqueString::compare(const DUniqueString & lhs, const DUniqueString & rhs)
+        {
+            if (&lhs == &rhs)
+                return 0;
+
+            return DString::compare(*(lhs._text()), *(rhs._text()));
+        }
+
         DString *
         DUniqueString::_text() const noexcept
         {
diff --git a/xo-expression2/src/expression2/DVariable.cpp b/xo-expression2/src/expression2/DVariable.cpp
index ac051387..8fc201a5 100644
--- a/xo-expression2/src/expression2/DVariable.cpp
+++ b/xo-expression2/src/expression2/DVariable.cpp
@@ -5,8 +5,8 @@
 
 #include "DVariable.hpp"
 #include "exprtype.hpp"
-#include <cstddef>
 #include <xo/indentlog/print/quoted.hpp>
+#include <cstddef>
 
 namespace xo {
     using xo::mm::ACollector;
diff --git a/xo-expression2/src/expression2/expression2_register_facets.cpp b/xo-expression2/src/expression2/expression2_register_facets.cpp
index 82bff638..a9edbc20 100644
--- a/xo-expression2/src/expression2/expression2_register_facets.cpp
+++ b/xo-expression2/src/expression2/expression2_register_facets.cpp
@@ -25,7 +25,7 @@
 #include <xo/expression2/GlobalSymtab.hpp>
 #include <xo/expression2/LocalSymtab.hpp>
 
-#include <xo/gc/detail/AGCObject.hpp>
+#include <xo/alloc2/gc/AGCObject.hpp>
 #include <xo/printable2/detail/APrintable.hpp>
 #include <xo/facet/FacetRegistry.hpp>
 #include <xo/indentlog/scope.hpp>
diff --git a/xo-gc/include/xo/gc/Collector.hpp b/xo-gc/include/xo/gc/Collector.hpp
deleted file mode 100644
index b4214036..00000000
--- a/xo-gc/include/xo/gc/Collector.hpp
+++ /dev/null
@@ -1,13 +0,0 @@
-/** @file Collector.hpp
- *
- *  @author Roland Conybeare, Dec 2025
- **/
-
-#pragma once
-
-#include "detail/ACollector.hpp"
-#include "detail/ICollector_Any.hpp"
-#include "detail/ICollector_Xfer.hpp"
-#include "detail/RCollector.hpp"
-
-/* end Collector.hpp */
diff --git a/xo-gc/include/xo/gc/GCObjectConversion.hpp b/xo-gc/include/xo/gc/GCObjectConversion.hpp
index 53148bfe..59ec12fa 100644
--- a/xo-gc/include/xo/gc/GCObjectConversion.hpp
+++ b/xo-gc/include/xo/gc/GCObjectConversion.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include <xo/facet/FacetRegistry.hpp>
 #include <xo/facet/obj.hpp>
diff --git a/xo-gc/include/xo/gc/detail/ICollector_DX1Collector.hpp b/xo-gc/include/xo/gc/detail/ICollector_DX1Collector.hpp
index 61010310..0475a535 100644
--- a/xo-gc/include/xo/gc/detail/ICollector_DX1Collector.hpp
+++ b/xo-gc/include/xo/gc/detail/ICollector_DX1Collector.hpp
@@ -3,8 +3,8 @@
  *  @author Roland Conybeare, Dec 2025
  **/
 
-#include "ACollector.hpp"
-#include "ICollector_Xfer.hpp"
+#include <xo/alloc2/gc/ACollector.hpp>
+#include <xo/alloc2/gc/ICollector_Xfer.hpp>
 #include "DX1Collector.hpp"
 
 namespace xo {
diff --git a/xo-gc/src/gc/DX1Collector.cpp b/xo-gc/src/gc/DX1Collector.cpp
index 8cbd0bbd..78d27340 100644
--- a/xo-gc/src/gc/DX1Collector.cpp
+++ b/xo-gc/src/gc/DX1Collector.cpp
@@ -3,13 +3,14 @@
  *  @author Roland Conybeare, Dec 2025
  **/
 
-#include "Allocator.hpp"
+#include <xo/alloc2/GCObject.hpp>
+#include <xo/alloc2/Allocator.hpp>
 #include "detail/IAllocator_DX1Collector.hpp"
 #include "detail/ICollector_DX1Collector.hpp"
 #include "arena/IAllocator_DArena.hpp"
-#include "xo/gc/DX1Collector.hpp"
-#include "xo/gc/DX1CollectorIterator.hpp"
-#include "generation.hpp"
+#include <xo/gc/DX1Collector.hpp>
+#include <xo/gc/DX1CollectorIterator.hpp>
+#include <xo/alloc2/generation.hpp>
 #include "object_age.hpp"
 #include <xo/facet/obj.hpp>
 #include <xo/indentlog/scope.hpp>
diff --git a/xo-gc/src/gc/ICollector_Any.cpp b/xo-gc/src/gc/ICollector_Any.cpp
index 301524fe..b39aa99e 100644
--- a/xo-gc/src/gc/ICollector_Any.cpp
+++ b/xo-gc/src/gc/ICollector_Any.cpp
@@ -3,7 +3,7 @@
  *  @author Roland Conybeare, Dec 2025
  **/
 
-#include "detail/ICollector_Any.hpp"
+#include "gc/ICollector_Any.hpp"
 #include <iostream>
 #include <exception>
 
diff --git a/xo-gc/src/gc/IGCObject_Any.cpp b/xo-gc/src/gc/IGCObject_Any.cpp
index 95c8cc84..10ff8f6a 100644
--- a/xo-gc/src/gc/IGCObject_Any.cpp
+++ b/xo-gc/src/gc/IGCObject_Any.cpp
@@ -2,7 +2,7 @@
  *
  **/
 
-#include "detail/IGCObject_Any.hpp"
+#include "gc/IGCObject_Any.hpp"
 #include <iostream>
 #include <exception>
 
diff --git a/xo-interpreter2/include/xo/interpreter2/DVsmDefContFrame.hpp b/xo-interpreter2/include/xo/interpreter2/DVsmDefContFrame.hpp
index 68c2510a..c0e6ed0f 100644
--- a/xo-interpreter2/include/xo/interpreter2/DVsmDefContFrame.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/DVsmDefContFrame.hpp
@@ -7,7 +7,7 @@
 
 #include "VsmInstr.hpp"
 #include <xo/expression2/DefineExpr.hpp>
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 
 namespace xo {
     namespace scm {
diff --git a/xo-interpreter2/include/xo/interpreter2/DVsmIfElseContFrame.hpp b/xo-interpreter2/include/xo/interpreter2/DVsmIfElseContFrame.hpp
index 3d4ace12..8efd9299 100644
--- a/xo-interpreter2/include/xo/interpreter2/DVsmIfElseContFrame.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/DVsmIfElseContFrame.hpp
@@ -7,7 +7,7 @@
 
 #include "VsmInstr.hpp"
 #include <xo/expression2/IfElseExpr.hpp>
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 
 namespace xo {
     namespace scm {
@@ -61,7 +61,7 @@ namespace xo {
             bool pretty(const ppindentinfo & ppii) const noexcept;
 
             ///@}
-            
+
         private:
             /** @defgroup scm-vsmevalsequenceframe-members member variables **/
             ///@{
diff --git a/xo-interpreter2/include/xo/interpreter2/DVsmSeqContFrame.hpp b/xo-interpreter2/include/xo/interpreter2/DVsmSeqContFrame.hpp
index cb63f0d4..6b543d8b 100644
--- a/xo-interpreter2/include/xo/interpreter2/DVsmSeqContFrame.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/DVsmSeqContFrame.hpp
@@ -7,7 +7,7 @@
 
 #include "VsmInstr.hpp"
 #include <xo/expression2/SequenceExpr.hpp>
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 
 namespace xo {
     namespace scm {
@@ -50,7 +50,7 @@ namespace xo {
             ///@{
 
             uint32_t incr_i_seq() noexcept { return ++(this->i_seq_); }
-            
+
             ///@}
             /** @defgroup scm-vsmevalsequenceframe-gcobject-facet gcobject facet **/
             ///@{
@@ -66,7 +66,7 @@ namespace xo {
             bool pretty(const ppindentinfo & ppii) const noexcept;
 
             ///@}
-            
+
         private:
             /** @defgroup scm-vsmevalsequenceframe-members member variables **/
             ///@{
diff --git a/xo-interpreter2/include/xo/interpreter2/VirtualSchematikaMachine.hpp b/xo-interpreter2/include/xo/interpreter2/VirtualSchematikaMachine.hpp
index 1bfa5ecb..ec7eda34 100644
--- a/xo-interpreter2/include/xo/interpreter2/VirtualSchematikaMachine.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/VirtualSchematikaMachine.hpp
@@ -13,7 +13,7 @@
 #include <xo/object2/RuntimeError.hpp>
 #include <xo/reader2/SchematikaReader.hpp>
 #include <xo/expression2/Expression.hpp>
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/abox.hpp>
 #include <variant>
 
diff --git a/xo-interpreter2/include/xo/interpreter2/define/IGCObject_DVsmDefContFrame.hpp b/xo-interpreter2/include/xo/interpreter2/define/IGCObject_DVsmDefContFrame.hpp
index 309a6ac7..bc3423d9 100644
--- a/xo-interpreter2/include/xo/interpreter2/define/IGCObject_DVsmDefContFrame.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/define/IGCObject_DVsmDefContFrame.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DVsmDefContFrame.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DClosure.hpp b/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DClosure.hpp
index fb863205..8507d640 100644
--- a/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DClosure.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DClosure.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DClosure.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DLocalEnv.hpp b/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DLocalEnv.hpp
index d318bb61..25db925a 100644
--- a/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DLocalEnv.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DLocalEnv.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DLocalEnv.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DVsmApplyClosureFrame.hpp b/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DVsmApplyClosureFrame.hpp
index 2baacd05..7db673e7 100644
--- a/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DVsmApplyClosureFrame.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DVsmApplyClosureFrame.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DVsmApplyClosureFrame.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DVsmApplyFrame.hpp b/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DVsmApplyFrame.hpp
index ca6d3b10..401a91d7 100644
--- a/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DVsmApplyFrame.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DVsmApplyFrame.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DVsmApplyFrame.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DVsmEvalArgsFrame.hpp b/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DVsmEvalArgsFrame.hpp
index 4a8ad18a..1a91c32f 100644
--- a/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DVsmEvalArgsFrame.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/detail/IGCObject_DVsmEvalArgsFrame.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DVsmEvalArgsFrame.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-interpreter2/include/xo/interpreter2/env/IGCObject_DGlobalEnv.hpp b/xo-interpreter2/include/xo/interpreter2/env/IGCObject_DGlobalEnv.hpp
index 1f0f9281..71ac3e49 100644
--- a/xo-interpreter2/include/xo/interpreter2/env/IGCObject_DGlobalEnv.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/env/IGCObject_DGlobalEnv.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DGlobalEnv.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-interpreter2/include/xo/interpreter2/env/IGCObject_DLocalEnv.hpp b/xo-interpreter2/include/xo/interpreter2/env/IGCObject_DLocalEnv.hpp
index d318bb61..25db925a 100644
--- a/xo-interpreter2/include/xo/interpreter2/env/IGCObject_DLocalEnv.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/env/IGCObject_DLocalEnv.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DLocalEnv.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-interpreter2/include/xo/interpreter2/ifelse/IGCObject_DVsmIfElseContFrame.hpp b/xo-interpreter2/include/xo/interpreter2/ifelse/IGCObject_DVsmIfElseContFrame.hpp
index 293dd70d..1d29a8ac 100644
--- a/xo-interpreter2/include/xo/interpreter2/ifelse/IGCObject_DVsmIfElseContFrame.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/ifelse/IGCObject_DVsmIfElseContFrame.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DVsmIfElseContFrame.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-interpreter2/include/xo/interpreter2/interpreter2_register_types.hpp b/xo-interpreter2/include/xo/interpreter2/interpreter2_register_types.hpp
index 1409d13a..b545f356 100644
--- a/xo-interpreter2/include/xo/interpreter2/interpreter2_register_types.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/interpreter2_register_types.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 
 namespace xo {
     namespace scm {
diff --git a/xo-interpreter2/include/xo/interpreter2/sequence/IGCObject_DVsmSeqContFrame.hpp b/xo-interpreter2/include/xo/interpreter2/sequence/IGCObject_DVsmSeqContFrame.hpp
index 1bdbe2ab..9b686c6c 100644
--- a/xo-interpreter2/include/xo/interpreter2/sequence/IGCObject_DVsmSeqContFrame.hpp
+++ b/xo-interpreter2/include/xo/interpreter2/sequence/IGCObject_DVsmSeqContFrame.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DVsmSeqContFrame.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-interpreter2/src/interpreter2/DVsmDefContFrame.cpp b/xo-interpreter2/src/interpreter2/DVsmDefContFrame.cpp
index 7b3b9e7a..2d5c9adf 100644
--- a/xo-interpreter2/src/interpreter2/DVsmDefContFrame.cpp
+++ b/xo-interpreter2/src/interpreter2/DVsmDefContFrame.cpp
@@ -5,7 +5,7 @@
 
 #include "DVsmDefContFrame.hpp"
 #include <xo/expression2/DefineExpr.hpp>
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 
 namespace xo {
     namespace scm {
diff --git a/xo-numeric/include/xo/numeric/NumericDispatch.hpp b/xo-numeric/include/xo/numeric/NumericDispatch.hpp
index 9de42160..1dc68a3d 100644
--- a/xo-numeric/include/xo/numeric/NumericDispatch.hpp
+++ b/xo-numeric/include/xo/numeric/NumericDispatch.hpp
@@ -7,7 +7,7 @@
 
 #include "NumericOps.hpp"
 #include <xo/procedure2/RuntimeContext.hpp>
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/arena/DArenaHashMap.hpp>
 #include <xo/reflectutil/typeseq.hpp>
 
diff --git a/xo-numeric/include/xo/numeric/NumericOps.hpp b/xo-numeric/include/xo/numeric/NumericOps.hpp
index b69a0338..580efcf1 100644
--- a/xo-numeric/include/xo/numeric/NumericOps.hpp
+++ b/xo-numeric/include/xo/numeric/NumericOps.hpp
@@ -7,7 +7,7 @@
 
 #include <xo/numeric/Numeric.hpp>
 #include <xo/procedure2/RuntimeContext.hpp>
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/facet/obj.hpp>
 
 namespace xo {
diff --git a/xo-object2/include/xo/object2/DArray.hpp b/xo-object2/include/xo/object2/DArray.hpp
index 879bb76c..55d5e068 100644
--- a/xo-object2/include/xo/object2/DArray.hpp
+++ b/xo-object2/include/xo/object2/DArray.hpp
@@ -5,8 +5,8 @@
 
 #pragma once
 
-#include <xo/gc/GCObject.hpp>
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/GCObject.hpp>
+#include <xo/alloc2/Collector.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include <xo/facet/obj.hpp>
 #include <xo/indentlog/print/ppindentinfo.hpp>
diff --git a/xo-object2/include/xo/object2/DBoolean.hpp b/xo-object2/include/xo/object2/DBoolean.hpp
index 69dd1c16..ee9fe3be 100644
--- a/xo-object2/include/xo/object2/DBoolean.hpp
+++ b/xo-object2/include/xo/object2/DBoolean.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include <xo/indentlog/print/ppindentinfo.hpp>
 #include <xo/facet/obj.hpp>
diff --git a/xo-object2/include/xo/object2/DDictionary.hpp b/xo-object2/include/xo/object2/DDictionary.hpp
index 1f028434..f5844088 100644
--- a/xo-object2/include/xo/object2/DDictionary.hpp
+++ b/xo-object2/include/xo/object2/DDictionary.hpp
@@ -7,8 +7,8 @@
 
 #include "DArray.hpp"
 #include "DString.hpp"
-#include <xo/gc/GCObject.hpp>
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/GCObject.hpp>
+#include <xo/alloc2/Collector.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include <xo/facet/obj.hpp>
 #include <xo/indentlog/print/ppindentinfo.hpp>
diff --git a/xo-object2/include/xo/object2/DFloat.hpp b/xo-object2/include/xo/object2/DFloat.hpp
index a46a990d..4e4be861 100644
--- a/xo-object2/include/xo/object2/DFloat.hpp
+++ b/xo-object2/include/xo/object2/DFloat.hpp
@@ -6,7 +6,7 @@
 #pragma once
 
 #include <xo/alloc2/Allocator.hpp>
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 #include <xo/facet/obj.hpp>
 #include <xo/indentlog/print/ppindentinfo.hpp>
 
diff --git a/xo-object2/include/xo/object2/DInteger.hpp b/xo-object2/include/xo/object2/DInteger.hpp
index b03693be..3fd13672 100644
--- a/xo-object2/include/xo/object2/DInteger.hpp
+++ b/xo-object2/include/xo/object2/DInteger.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include <xo/indentlog/print/ppindentinfo.hpp>
 #include <xo/facet/obj.hpp>
diff --git a/xo-object2/include/xo/object2/DList.hpp b/xo-object2/include/xo/object2/DList.hpp
index 39e0b584..50ab8dd7 100644
--- a/xo-object2/include/xo/object2/DList.hpp
+++ b/xo-object2/include/xo/object2/DList.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/facet/obj.hpp>
 #include <xo/indentlog/print/ppindentinfo.hpp>
 
diff --git a/xo-object2/include/xo/object2/DString.hpp b/xo-object2/include/xo/object2/DString.hpp
index a6cedb00..bb57e3da 100644
--- a/xo-object2/include/xo/object2/DString.hpp
+++ b/xo-object2/include/xo/object2/DString.hpp
@@ -6,7 +6,7 @@
 #pragma once
 
 #include <xo/alloc2/Allocator.hpp>
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 #include <xo/facet/obj.hpp>
 #include <xo/indentlog/print/ppindentinfo.hpp>
 #include <string_view>
@@ -15,6 +15,8 @@
 //#include <cstdio>
 
 namespace xo {
+    namespace mm { class ACollector; }
+
     namespace scm {
         /** @class DString
          *  @brief String implementation with gc hooks
@@ -111,14 +113,7 @@ namespace xo {
             static DString * printf(obj<AAllocator> mm,
                                     size_type cap,
                                     const char * fmt,
-                                    Args&&... args)
-            {
-                DString * result = DString::empty(mm, cap);
-                if (result) {
-                    result->sprintf(fmt, std::forward<Args>(args)...);
-                }
-                return result;
-            }
+                                    Args&&... args);
 
             ///@}
             /** @defgroup dstring-access access methods **/
@@ -252,8 +247,10 @@ namespace xo {
             /** clone string, using memory from allocator @p mm **/
             DString * shallow_copy(obj<AAllocator> mm) const noexcept;
 
-            /** fixup child pointers (trivial for DString, no children) **/
             size_type forward_children(obj<ACollector> gc) noexcept;
+            /** fixup child pointers (trivial for DString, no children)
+             *  note: cref so we can use forward decl
+             **/
 
             ///@}
 
@@ -285,6 +282,24 @@ namespace xo {
             ///@}
         };
 
+        /** create string using printf-style formatting.
+         *  Use memory from allocator @p mm with capacity @p cap.
+         *  Truncates if result exceeds capacity.
+         *  @return pointer to newly created DString
+         **/
+        template <typename... Args>
+        DString * DString::printf(obj<AAllocator> mm,
+                                  size_type cap,
+                                  const char * fmt,
+                                  Args&&... args)
+        {
+            DString * result = DString::empty(mm, cap);
+            if (result) {
+                result->sprintf(fmt, std::forward<Args>(args)...);
+            }
+            return result;
+        }
+
         inline std::ostream & operator<<(std::ostream & os, const DString * x) {
             if (x) {
                 os << std::string_view(*x);
diff --git a/xo-object2/include/xo/object2/String.hpp b/xo-object2/include/xo/object2/String.hpp
index 111b04fb..f3d0527b 100644
--- a/xo-object2/include/xo/object2/String.hpp
+++ b/xo-object2/include/xo/object2/String.hpp
@@ -9,4 +9,6 @@
 #include "string/IGCObject_DString.hpp"
 #include "string/IPrintable_DString.hpp"
 
+#include <xo/alloc2/Allocator.hpp>
+
 /* end String.hpp */
diff --git a/xo-object2/include/xo/object2/array/IGCObject_DArray.hpp b/xo-object2/include/xo/object2/array/IGCObject_DArray.hpp
index 9af6d3c7..08f78aa8 100644
--- a/xo-object2/include/xo/object2/array/IGCObject_DArray.hpp
+++ b/xo-object2/include/xo/object2/array/IGCObject_DArray.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DArray.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-object2/include/xo/object2/boolean/IGCObject_DBoolean.hpp b/xo-object2/include/xo/object2/boolean/IGCObject_DBoolean.hpp
index 1d90b60e..358aad18 100644
--- a/xo-object2/include/xo/object2/boolean/IGCObject_DBoolean.hpp
+++ b/xo-object2/include/xo/object2/boolean/IGCObject_DBoolean.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DBoolean.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-object2/include/xo/object2/dictionary/IGCObject_DDictionary.hpp b/xo-object2/include/xo/object2/dictionary/IGCObject_DDictionary.hpp
index 7f2e0ad9..7fe1bc55 100644
--- a/xo-object2/include/xo/object2/dictionary/IGCObject_DDictionary.hpp
+++ b/xo-object2/include/xo/object2/dictionary/IGCObject_DDictionary.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DDictionary.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-object2/include/xo/object2/number/IGCObject_DFloat.hpp b/xo-object2/include/xo/object2/number/IGCObject_DFloat.hpp
index 9a1dcbdc..b8e15b73 100644
--- a/xo-object2/include/xo/object2/number/IGCObject_DFloat.hpp
+++ b/xo-object2/include/xo/object2/number/IGCObject_DFloat.hpp
@@ -15,7 +15,7 @@
 
 #include "GCObject.hpp"
 #include <xo/object2/number/GCObjectConversion_DFloat.hpp>
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DFloat.hpp"
 
@@ -65,4 +65,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-object2/include/xo/object2/number/IGCObject_DInteger.hpp b/xo-object2/include/xo/object2/number/IGCObject_DInteger.hpp
index 1136b577..fd2ea642 100644
--- a/xo-object2/include/xo/object2/number/IGCObject_DInteger.hpp
+++ b/xo-object2/include/xo/object2/number/IGCObject_DInteger.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DInteger.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-object2/include/xo/object2/object2_register_facets.hpp b/xo-object2/include/xo/object2/object2_register_facets.hpp
index e419b794..7f42d5a0 100644
--- a/xo-object2/include/xo/object2/object2_register_facets.hpp
+++ b/xo-object2/include/xo/object2/object2_register_facets.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 
 namespace xo {
     namespace scm {
diff --git a/xo-object2/include/xo/object2/object2_register_types.hpp b/xo-object2/include/xo/object2/object2_register_types.hpp
index 5c61692d..5663b086 100644
--- a/xo-object2/include/xo/object2/object2_register_types.hpp
+++ b/xo-object2/include/xo/object2/object2_register_types.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 
 namespace xo {
     namespace scm {
diff --git a/xo-object2/include/xo/object2/sequence/ASequence.hpp b/xo-object2/include/xo/object2/sequence/ASequence.hpp
index 53d112e7..44f1d1cb 100644
--- a/xo-object2/include/xo/object2/sequence/ASequence.hpp
+++ b/xo-object2/include/xo/object2/sequence/ASequence.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 // includes (via {facet_includes})
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/facet/obj.hpp>
 #include <xo/facet/facet_implementation.hpp>
 #include <xo/facet/typeseq.hpp>
diff --git a/xo-object2/include/xo/object2/sequence/ISequence_Xfer.hpp b/xo-object2/include/xo/object2/sequence/ISequence_Xfer.hpp
index 42d6cb1b..e0511e41 100644
--- a/xo-object2/include/xo/object2/sequence/ISequence_Xfer.hpp
+++ b/xo-object2/include/xo/object2/sequence/ISequence_Xfer.hpp
@@ -13,7 +13,7 @@
 
 #pragma once
 
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 
 namespace xo {
 namespace scm {
diff --git a/xo-object2/include/xo/object2/string/IGCObject_DString.hpp b/xo-object2/include/xo/object2/string/IGCObject_DString.hpp
index 159b9e49..2a907f37 100644
--- a/xo-object2/include/xo/object2/string/IGCObject_DString.hpp
+++ b/xo-object2/include/xo/object2/string/IGCObject_DString.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DString.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-object2/src/object2/DList.cpp b/xo-object2/src/object2/DList.cpp
index 01d01d61..25770d01 100644
--- a/xo-object2/src/object2/DList.cpp
+++ b/xo-object2/src/object2/DList.cpp
@@ -6,7 +6,7 @@
 #include "DList.hpp"
 #include "list/IPrintable_DList.hpp"
 #include "list/IGCObject_DList.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/printable2/Printable.hpp>
 #include <xo/facet/FacetRegistry.hpp>
 #include <xo/facet/facet_implementation.hpp>
diff --git a/xo-object2/src/object2/DString.cpp b/xo-object2/src/object2/DString.cpp
index 69baa5d6..230fa4a4 100644
--- a/xo-object2/src/object2/DString.cpp
+++ b/xo-object2/src/object2/DString.cpp
@@ -4,12 +4,13 @@
  **/
 
 #include "DString.hpp"
+#include <xo/alloc2/Allocator.hpp>
 #include <xo/indentlog/print/pretty.hpp>
 #include <algorithm>
 #include <cstring>
 
 namespace xo {
-    using xo::facet::typeseq;
+    using xo::reflect::typeseq;
     using xo::print::ppdetail_atomic;
 
     namespace scm {
diff --git a/xo-object2/utest/DString.test.cpp b/xo-object2/utest/DString.test.cpp
index 39dffef5..53db8e7f 100644
--- a/xo-object2/utest/DString.test.cpp
+++ b/xo-object2/utest/DString.test.cpp
@@ -5,6 +5,7 @@
 
 #include "init_object2.hpp"
 #include "StringOps.hpp"
+#include <xo/alloc2/Allocator.hpp>
 #include <xo/alloc2/arena/IAllocator_DArena.hpp>
 #include <catch2/catch.hpp>
 #include <cctype>
diff --git a/xo-object2/utest/Printable.test.cpp b/xo-object2/utest/Printable.test.cpp
index 64736d22..2ca792fa 100644
--- a/xo-object2/utest/Printable.test.cpp
+++ b/xo-object2/utest/Printable.test.cpp
@@ -19,7 +19,7 @@
 #include <xo/object2/DInteger.hpp>
 #include <xo/object2/number/IGCObject_DInteger.hpp>
 
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 #include <xo/gc/DX1Collector.hpp>
 #include <xo/gc/detail/IAllocator_DX1Collector.hpp>
 #include <xo/gc/detail/ICollector_DX1Collector.hpp>
diff --git a/xo-object2/utest/X1Collector.test.cpp b/xo-object2/utest/X1Collector.test.cpp
index 90122c25..a2a2dec5 100644
--- a/xo-object2/utest/X1Collector.test.cpp
+++ b/xo-object2/utest/X1Collector.test.cpp
@@ -16,7 +16,7 @@
 #include "list/IGCObject_DList.hpp"
 
 #include <xo/gc/CollectorTypeRegistry.hpp>
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 #include <xo/gc/DX1Collector.hpp>
 
 #include <xo/gc/detail/IAllocator_DX1Collector.hpp>
diff --git a/xo-printable2/include/xo/printable2/Printable.hpp b/xo-printable2/include/xo/printable2/Printable.hpp
index 1789f1e0..cec3bc34 100644
--- a/xo-printable2/include/xo/printable2/Printable.hpp
+++ b/xo-printable2/include/xo/printable2/Printable.hpp
@@ -20,4 +20,6 @@
 
 #include "detail/ppdetail_Printable.hpp"
 
-/* end Printable.hpp */
\ No newline at end of file
+#include <xo/alloc2/Allocator.hpp>
+
+/* end Printable.hpp */
diff --git a/xo-procedure2/include/xo/procedure2/DPrimitive.hpp b/xo-procedure2/include/xo/procedure2/DPrimitive.hpp
index e458ce3a..5003ba02 100644
--- a/xo-procedure2/include/xo/procedure2/DPrimitive.hpp
+++ b/xo-procedure2/include/xo/procedure2/DPrimitive.hpp
@@ -8,7 +8,7 @@
 #include "RuntimeContext.hpp"
 #include <xo/object2/DArray.hpp>
 #include <xo/gc/GCObjectConversion.hpp>
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/reflect/Reflect.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include <xo/facet/FacetRegistry.hpp>
diff --git a/xo-procedure2/include/xo/procedure2/DPrimitive_gco_0.hpp b/xo-procedure2/include/xo/procedure2/DPrimitive_gco_0.hpp
index 7e5633cf..b6b02a94 100644
--- a/xo-procedure2/include/xo/procedure2/DPrimitive_gco_0.hpp
+++ b/xo-procedure2/include/xo/procedure2/DPrimitive_gco_0.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include "DPrimitive.hpp"
 
 namespace xo {
diff --git a/xo-procedure2/include/xo/procedure2/DPrimitive_gco_1_gco.hpp b/xo-procedure2/include/xo/procedure2/DPrimitive_gco_1_gco.hpp
index 56e540d6..8e939677 100644
--- a/xo-procedure2/include/xo/procedure2/DPrimitive_gco_1_gco.hpp
+++ b/xo-procedure2/include/xo/procedure2/DPrimitive_gco_1_gco.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include "DPrimitive.hpp"
 
 namespace xo {
diff --git a/xo-procedure2/include/xo/procedure2/DPrimitive_gco_2_gco_gco.hpp b/xo-procedure2/include/xo/procedure2/DPrimitive_gco_2_gco_gco.hpp
index 78dd26b9..a5895af3 100644
--- a/xo-procedure2/include/xo/procedure2/DPrimitive_gco_2_gco_gco.hpp
+++ b/xo-procedure2/include/xo/procedure2/DPrimitive_gco_2_gco_gco.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include "DPrimitive.hpp"
 
 namespace xo {
diff --git a/xo-procedure2/include/xo/procedure2/DPrimitive_gco_3_dict_string_gco.hpp b/xo-procedure2/include/xo/procedure2/DPrimitive_gco_3_dict_string_gco.hpp
index c0dce657..29f18b23 100644
--- a/xo-procedure2/include/xo/procedure2/DPrimitive_gco_3_dict_string_gco.hpp
+++ b/xo-procedure2/include/xo/procedure2/DPrimitive_gco_3_dict_string_gco.hpp
@@ -7,7 +7,7 @@
 
 #include <xo/object2/Dictionary.hpp>
 #include <xo/object2/String.hpp>
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include "DPrimitive.hpp"
 
 namespace xo {
diff --git a/xo-procedure2/include/xo/procedure2/detail/AProcedure.hpp b/xo-procedure2/include/xo/procedure2/detail/AProcedure.hpp
index eb119fbd..a5c41b41 100644
--- a/xo-procedure2/include/xo/procedure2/detail/AProcedure.hpp
+++ b/xo-procedure2/include/xo/procedure2/detail/AProcedure.hpp
@@ -15,7 +15,7 @@
 
 // includes (via {facet_includes})
 #include "RuntimeContext.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/facet/obj.hpp>
 #include <xo/facet/facet_implementation.hpp>
 #include <xo/facet/typeseq.hpp>
diff --git a/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_0.hpp b/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_0.hpp
index 91ff1833..cfc5d192 100644
--- a/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_0.hpp
+++ b/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_0.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DPrimitive_gco_0.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_1_gco.hpp b/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_1_gco.hpp
index 190a92c7..d2dd1d3e 100644
--- a/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_1_gco.hpp
+++ b/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_1_gco.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DPrimitive_gco_1_gco.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_2_gco_gco.hpp b/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_2_gco_gco.hpp
index f6bfe6ed..68fa0e53 100644
--- a/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_2_gco_gco.hpp
+++ b/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_2_gco_gco.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DPrimitive_gco_2_gco_gco.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_3_dict_string_gco.hpp b/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_3_dict_string_gco.hpp
index abb30bca..4f851cfa 100644
--- a/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_3_dict_string_gco.hpp
+++ b/xo-procedure2/include/xo/procedure2/detail/IGCObject_DPrimitive_gco_3_dict_string_gco.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "GCObject.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/alloc2/Allocator.hpp>
 #include "DPrimitive_gco_3_dict_string_gco.hpp"
 
@@ -64,4 +64,4 @@ namespace xo {
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/xo-procedure2/include/xo/procedure2/detail/IProcedure_Xfer.hpp b/xo-procedure2/include/xo/procedure2/detail/IProcedure_Xfer.hpp
index 0be093fb..59742f32 100644
--- a/xo-procedure2/include/xo/procedure2/detail/IProcedure_Xfer.hpp
+++ b/xo-procedure2/include/xo/procedure2/detail/IProcedure_Xfer.hpp
@@ -14,7 +14,7 @@
 #pragma once
 
 #include "RuntimeContext.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 
 namespace xo {
 namespace scm {
diff --git a/xo-procedure2/include/xo/procedure2/procedure2_register_facets.hpp b/xo-procedure2/include/xo/procedure2/procedure2_register_facets.hpp
index 219da3d4..2a7128cc 100644
--- a/xo-procedure2/include/xo/procedure2/procedure2_register_facets.hpp
+++ b/xo-procedure2/include/xo/procedure2/procedure2_register_facets.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 
 namespace xo {
     namespace scm {
diff --git a/xo-procedure2/include/xo/procedure2/procedure2_register_types.hpp b/xo-procedure2/include/xo/procedure2/procedure2_register_types.hpp
index be0170aa..98b0c5f7 100644
--- a/xo-procedure2/include/xo/procedure2/procedure2_register_types.hpp
+++ b/xo-procedure2/include/xo/procedure2/procedure2_register_types.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 
 namespace xo {
     namespace scm {
diff --git a/xo-procedure2/src/procedure2/DPrimitive.cpp b/xo-procedure2/src/procedure2/DPrimitive.cpp
index ab335d8d..44903cc2 100644
--- a/xo-procedure2/src/procedure2/DPrimitive.cpp
+++ b/xo-procedure2/src/procedure2/DPrimitive.cpp
@@ -4,7 +4,7 @@
  **/
 
 #include "DPrimitive.hpp"
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 
 namespace xo {
     namespace scm {
diff --git a/xo-procedure2/src/procedure2/procedure2_register_facets.cpp b/xo-procedure2/src/procedure2/procedure2_register_facets.cpp
index b7b595e5..0fb14fe7 100644
--- a/xo-procedure2/src/procedure2/procedure2_register_facets.cpp
+++ b/xo-procedure2/src/procedure2/procedure2_register_facets.cpp
@@ -10,7 +10,7 @@
 #include "Primitive_gco_2_gco_gco.hpp"
 #include "Primitive_gco_3_dict_string_gco.hpp"
 
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/printable2/Printable.hpp>
 #include <xo/facet/FacetRegistry.hpp>
 #include <xo/indentlog/scope.hpp>
diff --git a/xo-reader2/include/xo/reader2/reader2_register_types.hpp b/xo-reader2/include/xo/reader2/reader2_register_types.hpp
index a7e6c0e1..1d8fea34 100644
--- a/xo-reader2/include/xo/reader2/reader2_register_types.hpp
+++ b/xo-reader2/include/xo/reader2/reader2_register_types.hpp
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <xo/gc/Collector.hpp>
+#include <xo/alloc2/Collector.hpp>
 
 namespace xo {
     namespace scm {
diff --git a/xo-reader2/src/reader2/DExpectExprSsm.cpp b/xo-reader2/src/reader2/DExpectExprSsm.cpp
index 57cf3836..aef5c7a4 100644
--- a/xo-reader2/src/reader2/DExpectExprSsm.cpp
+++ b/xo-reader2/src/reader2/DExpectExprSsm.cpp
@@ -19,7 +19,7 @@
 #include <xo/object2/Integer.hpp>
 #include <xo/object2/Float.hpp>
 #include <xo/object2/String.hpp>
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 #include <xo/facet/facet_implementation.hpp>
 
 #ifdef NOT_YET
diff --git a/xo-reader2/src/reader2/DToplevelSeqSsm.cpp b/xo-reader2/src/reader2/DToplevelSeqSsm.cpp
index 0473660f..493c745e 100644
--- a/xo-reader2/src/reader2/DToplevelSeqSsm.cpp
+++ b/xo-reader2/src/reader2/DToplevelSeqSsm.cpp
@@ -29,7 +29,7 @@
 #include <xo/object2/DBoolean.hpp>
 #include <xo/object2/boolean/IGCObject_DBoolean.hpp>
 
-#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/GCObject.hpp>
 
 namespace xo {
     using xo::scm::DProgressSsm;