diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4b7c1036..14226afa 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -47,6 +47,13 @@ install(
     DESTINATION ${CMAKE_INSTALL_BINDIR}
 )
 
+install(
+    FILES
+    "etc/xo/subsystem-list"
+    PERMISSIONS OWNER_READ GROUP_READ WORLD_READ
+    DESTINATION ${CMAKE_INSTALL_DATADIR}/etc/xo
+)
+
 # The cmake template gen-ccov.in should be expanded in downstream project;
 # to pickup downstream project's PROJECT_SOURCE_DIR / PROJECT_BINARY_DIR
 #
diff --git a/bin/xo-build.in b/bin/xo-build.in
index 49bbf4d6..194ce3df 100644
--- a/bin/xo-build.in
+++ b/bin/xo-build.in
@@ -1,7 +1,12 @@
 #!/usr/bin/env bash
 
 usage() {
-    echo "$0 [-u|--usage|-h|--help] [--xoname=NAME] [--repo]"
+    cat <<EOF
+$0 [-u|--usage|-h|--help]
+    [--list] [-n] [--xoname=NAME]
+    [--repo|--clone|--configure|--build|--install]
+    [-S=SOURCEDIR] [-B=BUILDDIR]
+EOF
 }
 
 help() {
@@ -14,7 +19,7 @@ fetch and/or build xo component libraries
 Options:
   -u | --usage      brief help message
   -h | --help       this help message
-  --list            list known xo library
+  --list            list known xo libraries
   -n                dry-run: don't actually invoke state-changing commands
   --xoname=NAME     operate on xo subsystem NAME
   --repo            report github repo for NAME
@@ -23,6 +28,8 @@ Options:
                     Will use NAME/.build as build directory
   --build           run cmake build for xo library NAME in immediate subdir
   --install         run cmake install for xo library NAME in immediate subdir
+  -S=SOURCEDIR      override path/to/source
+  -B=BUILDDIR       override path/to/build
 EOF
 }
 
@@ -33,6 +40,8 @@ clone_flag=0
 configure_flag=0
 build_flag=0
 install_flag=0
+pathtosource=
+pathtobuild=
 
 while [[ $# > 0 ]]; do
     case "$1" in
@@ -45,6 +54,20 @@ while [[ $# > 0 ]]; do
         -n)
             noop_flag=1
             ;;
+        -S)
+            shift
+            pathtosource=$1
+            ;;
+        -S=*)
+            pathtosource="${1#*=}"
+            ;;
+        -B)
+            shift
+            pathtobuild=$1
+            ;;
+        -B=*)
+            pathtobuild="${1#*=}"
+            ;;
         --list)
             cmd='list'
             ;;
@@ -78,21 +101,20 @@ while [[ $# > 0 ]]; do
     shift
 done
 
+echo xoname=$xoname pathtosource=$pathtosource pathtobuild=$pathtobuild
+
+if [[ -z "$pathtosource" ]]; then
+    pathtosource=$xoname
+fi
+
+if [[ -z "$pathtobuild" ]]; then
+    pathtobuild=$xoname/.build
+fi
+
+SUBSYSTEMLIST_FILE=@CMAKE_INSTALL_FULL_DATADIR@/etc/xo/subsystem-list
+
 subsystem_list() {
-    cat <<EOF
-xo-cmake
-xo-indentlog
-xo-refcnt
-xo-subsys
-xo-ratio
-xo-reflect
-xo-pyutil
-xo-pyreflect
-xo-expression
-xo-pyexpression
-xo-jit
-xo-pyjit
-EOF
+    cat ${SUBSYSTEMLIST_FILE}
 }
 
 XO_REPO_STEM="https://github.com/Rconybea"
@@ -101,9 +123,6 @@ repo() {
     xoname=$1
 
     case "$xoname" in
-        xo-cmake)
-            echo "${XO_REPO_STEM}/xo-cmake.git"
-            ;;
         xo-indentlog)
             echo "${XO_REPO_STEM}/indentlog.git"
             ;;
@@ -113,33 +132,16 @@ repo() {
         xo-subsys)
             echo "${XO_REPO_STEM}/subsys.git"
             ;;
-        xo-ratio)
-            echo "${XO_REPO_STEM}/xo-ratio.git"
-            ;;
         xo-reflect)
             echo "${XO_REPO_STEM}/reflect.git"
             ;;
-        xo-pyutil)
-            echo "${XO_REPO_STEM}/xo-pyutil.git"
-            ;;
-        xo-pyreflect)
-            echo "${XO_REPO_STEM}/xo-pyreflect.git"
-            ;;
-        xo-expression)
-            echo "${XO_REPO_STEM}/xo-expression.git"
-            ;;
-        xo-pyexpression)
-            echo "${XO_REPO_STEM}/xo-pyexpression.git"
-            ;;
-        xo-jit)
-            echo "${XO_REPO_STEM}/xo-jit.git"
-            ;;
-        xo-pyjit)
-            echo "${XO_REPO_STEM}/xo-pyjit.git"
-            ;;
         *)
-            echo "$0: unknown xo component [${xoname}]"
-            return 1
+            if grep -q $1 ${SUBSYSTEMLIST_FILE}; then
+                echo "${XO_REPO_STEM}/${1}.git"
+            else
+                >&2 echo "$0: unknown xo component [${xoname}]"
+                return 1
+            fi
     esac
 
     return 0
@@ -183,7 +185,7 @@ fi
 
 if [[ $configure_flag -eq 1 ]]; then
     if [[ -n "$xoname" ]]; then
-        cmd="cmake -DCMAKE_INSTALL_PREFIX=@CMAKE_INSTALL_PREFIX@ -S $xoname -B $xoname/.build"
+        cmd="cmake -DCMAKE_INSTALL_PREFIX=@CMAKE_INSTALL_PREFIX@ -S $pathtosource -B $pathtobuild"
 
         if [[ $noop_flag -eq 1 ]]; then
             echo $cmd
@@ -195,7 +197,7 @@ fi
 
 if [[ $build_flag -eq 1 ]]; then
     if [[ -n "$xoname" ]]; then
-        cmd="cmake --build $xoname/.build -j"
+        cmd="cmake --build $pathtobuild -j"
 
         if [[ $noop_flag -eq 1 ]]; then
             echo $cmd
@@ -207,7 +209,7 @@ fi
 
 if [[ $install_flag -eq 1 ]]; then
     if [[ -n "$xoname" ]]; then
-        cmd="cmake --install $xoname/.build"
+        cmd="cmake --install $pathtobuild"
 
         if [[ $noop_flag -eq 1 ]]; then
             echo $cmd
diff --git a/bin/xo-cmake-config.in b/bin/xo-cmake-config.in
index 4950617e..bbea1361 100755
--- a/bin/xo-cmake-config.in
+++ b/bin/xo-cmake-config.in
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
 usage() {
-    echo "$0 [-u|--usage|-h|--help|--lcov-exe|--genhtml-exe|--lcov-harness-exe|--gen-ccov-template|--cmake-module-path]" 1>&2
+    echo "$0 [-u|--usage|-h|--help|--lcov-exe|--genhtml-exe|--lcov-harness-exe|--gen-ccov-template|--cmake-module-path|--subsystem-list]" 1>&2
 }
 
 help() {
@@ -20,6 +20,7 @@ Options:
   --lcov-harness-exe  report path to 'xo-cmake-lcov-harness' executable
   --gen-ccov-template report path to 'gen-ccov.in' template
   --doxygen-template  report path to 'Doxyfile.in' template
+  --subsystem-list    report path to 'subsystem-ilst'
 
 EOF
 }
@@ -50,6 +51,9 @@ while [[ $# > 0 ]]; do
         --doxygen-template)
             cmd='doxygen_template'
             ;;
+        --subsystem-list)
+            cmd='subsystem_list'
+            ;;
         *)
             usage
             exit 1
@@ -77,4 +81,6 @@ elif [[ $cmd == 'gen_ccov_template' ]]; then
     echo -n @CMAKE_INSTALL_FULL_DATADIR@/xo-macros/gen-ccov.in
 elif [[ $cmd == 'doxygen_template' ]]; then
     echo -n @CMAKE_INSTALL_FULL_DATADIR@/xo-macros/Doxyfile.in
+elif [[ $cmd == 'subsystem_list' ]]; then
+    echo -n @CMAKE_INSTALL_FULL_DATADIR@/etc/xo/subsystem-list
 fi
diff --git a/etc/xo/subsystem-list b/etc/xo/subsystem-list
new file mode 100644
index 00000000..d1dcf6c7
--- /dev/null
+++ b/etc/xo/subsystem-list
@@ -0,0 +1,38 @@
+xo-cmake
+xo-indentlog
+xo-refcnt
+xo-subsys
+xo-randomgen
+xo-ordinaltree
+xo-pyutil
+xo-flatstring
+xo-reflectutil
+xo-reflect
+xo-pyreflect
+xo-ratio
+xo-unit
+xo-pyunit
+xo-expression
+xo-pyexpression
+xo-tokenizer
+xo-reader
+xo-jit
+xo-pyjit
+xo-callback
+xo-webutil
+xo-pywebutil
+xo-printjson
+xo-pyprintjson
+xo-reactor
+xo-pyreactor
+xo-websock
+xo-pywebsock
+xo-statistics
+xo-distribution
+xo-pydistribution
+xo-simulator
+xo-pysimulator
+xo-process
+xo-pyprocess
+xo-kalmanfilter
+xo-pykalmanfilter