diff --git a/src/make.tcl b/src/make.tcl
index 1f0c0344..eca518ab 100644
--- a/src/make.tcl
+++ b/src/make.tcl
@@ -361,47 +361,55 @@ if {[catch {exec sdx help} errM]} {
 }
 
 
-if {[llength $runtimes] > 1} {
-    puts stderr "Found multiple runtimes in $rtfolder ($runtimes)  - unable to proceed - currently limited to one."
-    exit 3
-}
+#if {[llength $runtimes] > 1} {
+#    puts stderr "Found multiple runtimes in $rtfolder ($runtimes)  - unable to proceed - currently limited to one."
+#    exit 3
+#}
 
 
+set vfs_folder_changes [dict create] ;#cache whether each .vfs folder has changes so we don't re-run tests if building from same .vfs with multiple runtime executables
 
 set installername "make.tcl"
 # -- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
-set runtimefile [lindex $runtimes 0]
-#sdx *may* be pointed to use the runtime we use to build the kit, or the user may manually use this runtime if they don't have tclsh
-#sdx will complain if the same runtime is used for the shell as is used in the -runtime argument - so we make a copy (REVIEW)
-#if {![file exists $buildfolder/buildruntime.exe]} {
-#    file copy $rtfolder/$runtimefile $buildfolder/buildruntime.exe
-#}
+#set runtimefile [lindex $runtimes 0]
+foreach  runtimefile $runtimes {
+    #runtimefile e.g tclkit86bi.exe
+
+    #sdx *may* be pointed to use the runtime we use to build the kit, or the user may manually use this runtime if they don't have tclsh
+    #sdx will complain if the same runtime is used for the shell as is used in the -runtime argument - so we make a copy (REVIEW)
+    #if {![file exists $buildfolder/buildruntime.exe]} {
+    #    file copy $rtfolder/$runtimefile $buildfolder/buildruntime.exe
+    #}
+
+    set basedir $buildfolder
+    set config [dict create\
+        -make-step copy_runtime\
+    ]
+    lassign [punkcheck::start_installer_event $basedir/.punkcheck $installername $rtfolder $buildfolder $config] _eventid punkcheck_eventid _recordset record_list
+
 
-set basedir $buildfolder
-set config [dict create\
-    -make-step copy_runtime\
-]
-lassign [punkcheck::start_installer_event $basedir/.punkcheck $installername $rtfolder $buildfolder $config] _eventid punkcheck_eventid _recordset record_list
-
-
-set target_relpath [punkcheck::lib::path_relative $basedir $buildfolder/buildruntime.exe]
-set file_record [punkcheck::installfile_begin $basedir $target_relpath $installername -eventid $punkcheck_eventid]
-# -- --- --- --- --- ---
-set source_relpath [punkcheck::lib::path_relative $basedir $rtfolder/$runtimefile]
-set file_record [punkcheck::installfile_add_source_and_fetch_metadata $basedir $source_relpath $file_record]
-# -- --- --- --- --- ---
-set changed_unchanged [punkcheck::recordlist::file_install_record_source_changes [lindex [dict get $file_record body] end]]
-if {[llength [dict get $changed_unchanged changed]]} {
-    set file_record [punkcheck::installfile_started_install $basedir $file_record]
+    set target_relpath [punkcheck::lib::path_relative $basedir $buildfolder/build_$runtimefile]
+    set file_record [punkcheck::installfile_begin $basedir $target_relpath $installername -eventid $punkcheck_eventid]
     # -- --- --- --- --- ---
-    puts stdout "Copying runtime from $rtfolder/$runtimefile to $buildfolder/buildruntime.exe"
-    file copy -force $rtfolder/$runtimefile $buildfolder/buildruntime.exe
+    set source_relpath [punkcheck::lib::path_relative $basedir $rtfolder/$runtimefile]
+    set file_record [punkcheck::installfile_add_source_and_fetch_metadata $basedir $source_relpath $file_record]
     # -- --- --- --- --- ---
-    set file_record [punkcheck::installfile_finished_install $basedir $file_record]
-} else {
-    puts stderr "."
-    set file_record [punkcheck::installfile_skipped_install $basedir $file_record]
+    set changed_unchanged [punkcheck::recordlist::file_install_record_source_changes [lindex [dict get $file_record body] end]]
+    if {[llength [dict get $changed_unchanged changed]]} {
+        set file_record [punkcheck::installfile_started_install $basedir $file_record]
+        # -- --- --- --- --- ---
+        puts stdout "Copying runtime from $rtfolder/$runtimefile to $buildfolder/build_$runtimefile"
+        file copy -force $rtfolder/$runtimefile $buildfolder/build_$runtimefile
+        # -- --- --- --- --- ---
+        set file_record [punkcheck::installfile_finished_install $basedir $file_record]
+    } else {
+        puts stderr "."
+        set file_record [punkcheck::installfile_skipped_install $basedir $file_record]
+    }
+
+
 }
+
 # -- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
 
 
@@ -413,7 +421,7 @@ cd [file dirname $buildfolder]
 #Simply rebuilding all the time may be close the speed of detecting change anyway - and almost certainly much faster when there is a change.
 #Using first mtime encountered that is later than target is another option - but likely to be highly variable in speed. Last file in the tree could happen to be the latest, and this mechanism doesn't handle build on reversion to older source.
 foreach vfs $vfs_folders {
-
+    
     set vfsname [file rootname $vfs]
     puts stdout "  Processing vfs $sourcefolder/$vfs"
     puts stdout "  ------------------------------------"
@@ -540,7 +548,7 @@ foreach vfs $vfs_folders {
         if {[file exists $buildfolder/$targetexe]} {
             puts stderr "deleting existing $buildfolder/$targetexe"
             if {[catch {
-                file delete $sourcefolder/_build/$targetexe
+                file delete $buildfolder/$targetexe
             } msg]} {
                 puts stderr "Failed to delete $buildfolder/$targetexe"
                 exit 4
@@ -548,7 +556,7 @@ foreach vfs $vfs_folders {
         }
 
         if {$::tcl_platform(platform) eq "windows"} {
-            file rename $buildfolder/$vfsname $sourcefolder/_build/${vfsname}.exe 
+            file rename $buildfolder/$vfsname $buildfolder/${vfsname}.exe 
         }
 
         after 200