diff --git a/clean-classic/macos-x64/build.sh b/clean-classic/macos-x64/build.sh
index 73fbbd5da0ba716153dd97bd76954be1be6817f7..d31a1a3eaae6cda8f46dd334a3a70f2ffc95f141 100755
--- a/clean-classic/macos-x64/build.sh
+++ b/clean-classic/macos-x64/build.sh
@@ -9,6 +9,7 @@ export BOOTCOMPILERPATH=$PWD/boot_compiler/bin:$PWD/boot_compiler/lib/exe:$PATH
 export PATH=$BOOTCOMPILERPATH
 ./clean-classic/macos-x64/build_htoclean.sh
 ./clean-classic/macos-x64/build_clc_larger_stack.sh
+./clean-classic/macos-x64/build_clc_itasks_larger_stack.sh
 ./clean-classic/macos-x64/build_batch_build.sh
 ./clean-classic/macos-x64/build_libraries.sh
 ./clean-classic/macos-x64/build_language_report.sh
@@ -23,12 +24,14 @@ mkdir step0
 mv stdenv step0/
 mv clean-libraries step0/
 mv compiler step0/
+mv compiler_itask step0/
 mv write_clean_manual step0/
 mv htoclean step0/
 mv clean-ide step0/
 mv clean-platform step0/
 ./clean-classic/macos-x64/build_htoclean.sh
 ./clean-classic/macos-x64/build_clc.sh
+./clean-classic/macos-x64/build_clc_itasks.sh
 ./clean-classic/macos-x64/build_batch_build.sh
 ./clean-classic/macos-x64/build_libraries.sh
 ./clean-classic/macos-x64/build_language_report.sh
diff --git a/clean-classic/macos-x64/build_clc_itasks.sh b/clean-classic/macos-x64/build_clc_itasks.sh
index 2212da360b3a087d9e0e776742b50b60a7505975..5a066110416f2c653c448f8a519a428bcab5e25b 100755
--- a/clean-classic/macos-x64/build_clc_itasks.sh
+++ b/clean-classic/macos-x64/build_clc_itasks.sh
@@ -1,19 +1,10 @@
 set -e
-# ./checkout.sh libraries/ArgEnvUnix
-if test ! -d libraries/ArgEnvUnix ; then
-  ./svn_checkout.sh clean-libraries/trunk/Libraries/ArgEnvUnix libraries/ArgEnvUnix
-fi
-# ./checkout.sh compiler
-./svn_checkout.sh clean-compiler/branches/itask compiler
+# ./git_clone.sh clean-compiler-and-rts/compiler.git compiler
+(cd git/compiler; git checkout origin/itask -- .)
+mkdir compiler_itask
+mv git/compiler/* compiler_itask/
 
-cd compiler
+cd compiler_itask
 clm -ABC -nw -ci -I backend -I frontend -I main -I main/Unix -IL ArgEnv backendconvert
-cd unix
-sed "s/-h 80M -s 4m/-h 256m -s 8m/" <make.macosx64.sh >make.macosx64.sh_
-rm -f make.macosx64.sh
-mv make.macosx64.sh_ make.macosx64.sh
-chmod +x make.macosx64.sh
-cd ..
 unix/make.macosx64.sh
 cd ..
-
diff --git a/clean-classic/macos-x64/build_clc_itasks_larger_stack.sh b/clean-classic/macos-x64/build_clc_itasks_larger_stack.sh
new file mode 100755
index 0000000000000000000000000000000000000000..c21d2d6cbfbda89c7462102934b2d6eeeb64a401
--- /dev/null
+++ b/clean-classic/macos-x64/build_clc_itasks_larger_stack.sh
@@ -0,0 +1,15 @@
+set -e
+# ./git_clone.sh clean-compiler-and-rts/compiler.git compiler
+(cd git/compiler; git checkout origin/itask -- .)
+mkdir compiler_itask
+mv git/compiler/* compiler_itask/
+
+cp clm/clm boot_compiler/bin/clm_
+(cd boot_compiler/bin; ./patch_bin clm_ `./patch_bin clm CLEANPATH | tr -d '='` )
+(cd boot_compiler/bin; ./patch_bin clm_ `./patch_bin clm CLEANLIB | tr -d '='` )
+(cd boot_compiler/bin; ./patch_bin clm_ `./patch_bin clm CLEANILIB | tr -d '='` )
+
+cd compiler_itask
+clm_ -aC,-s,2m -fusion -ABC -nw -ci -I backend -I frontend -I main -I main/Unix -IL ArgEnv backendconvert
+unix/make.macosx64.sh
+cd ..
diff --git a/clean-classic/macos-x64/build_clean.sh b/clean-classic/macos-x64/build_clean.sh
index e4d06e7be39431f136e30b32c1340bf243e65dd6..ae442678d728a3c7a15f08da215b1fafeae193f8 100755
--- a/clean-classic/macos-x64/build_clean.sh
+++ b/clean-classic/macos-x64/build_clean.sh
@@ -22,6 +22,7 @@ cp clean-ide/cpm/cpm clean/bin
 
 mkdir -p clean/exe
 cp compiler/cocl clean/exe
+cp compiler_itask/cocl clean/exe/cocl_itask
 cp code-generator/cg clean/exe
 
 mkdir -p clean/doc
diff --git a/clean-classic/macos-x64/cleanup.sh b/clean-classic/macos-x64/cleanup.sh
index cbb5c9919a97205d24b7f99565ca82c99f46adc3..2c94fb83a61b1ce223da64f0410ce92db486d1df 100755
--- a/clean-classic/macos-x64/cleanup.sh
+++ b/clean-classic/macos-x64/cleanup.sh
@@ -4,6 +4,7 @@ rm -rf code-generator
 rm -rf clm
 rm -rf run-time-system
 rm -rf compiler
+rm -rf compiler_itask
 rm -rf clean-libraries
 rm -rf clean-ide
 rm -rf htoclean
diff --git a/clean-classic/macos-x64/txt/Makefile b/clean-classic/macos-x64/txt/Makefile
index 94d0d4afef8d467ffcd537184c97992724ff12c9..391f7916c15ee1e8e7bd93835a11c4bc0f014733 100755
--- a/clean-classic/macos-x64/txt/Makefile
+++ b/clean-classic/macos-x64/txt/Makefile
@@ -77,7 +77,7 @@ PATCH_BIN = $(CURRENTDIR)/bin/patch_bin
 # Binaries
 #
 BIN_FILES = clm htoclean
-EXE_FILES = cocl cg
+EXE_FILES = cocl cocl_itask cg
 
 INSTALL_BIN_FILES = $(BIN_FILES:%=$(INSTALL_BIN_DIR)/%)
 INSTALL_CLM = $(INSTALL_BIN_DIR)/clm
diff --git a/clean-classic/macos-x64/txt/README b/clean-classic/macos-x64/txt/README
index 98e34f3afd6334d742ef263a3846140ad7051d2d..a4d87f16e8f79ea2b170b1147d00d799b9f2e3b8 100755
--- a/clean-classic/macos-x64/txt/README
+++ b/clean-classic/macos-x64/txt/README
@@ -1,31 +1,52 @@
-# Using Clean
+Installing Clean
+================
 
-Compiling Clean programs on a mac can be done using one of the following tools:
+By default the Clean system is installed in the current directory.
+You can override these defaults by changing INSTALL_BIN_DIR, INSTALL_LIB_DIR, INSTALL_MAN_DIR in the Makefile.
+
+To install the Clean system type:
+
+	make
+
+Using Clean
+===========
+
+Compiling Clean programs on linux can be done using one of the following tools:
 
 - clm: A build tool for simple projects. All compilation options and paths to libraries are specified as command line arguments
+
 - cpm: A build tool that allows you to specify build configurations of programs in Clean project files (.prj).
-       You can use cpm create or edit project files and build those projects.
+       You can use cpm to create or edit project files and build those projects.
 
-Both tools rely on the environment variable `CLEAN_HOME` to point to where you installed Clean to find libraries and executables.
-So for example if you have unpacked this package to `/Users/myusername/clean` you should the following exports to your .bashrc/.profile/etc
-```
-export CLEAN_HOME=/Users/myusername/clean
-export PATH=$PATH:$CLEAN_HOME/bin
-```
+  cpm relies on the environment variable `CLEAN_HOME` to point to where you installed Clean to find libraries and executables.
+  So for example if you have installed clean in '/Users/myusername/clean' you should add the following exports to your .bashrc/.profile/etc
 
-# Dependencies 
+  export CLEAN_HOME=/Users/myusername/clean
+  export PATH=$PATH:$CLEAN_HOME/bin
+
+Dependencies
+============
 
 Clean uses the linker and assembler from Apple. These are not
 installed by default. Therefore first Apple's XCode must be installed.
 For more information on XCode see:
 https://developer.apple.com/xcode/
 
-# More Info
+Compiling the example programs
+==============================
+
+The directory 'examples/SmallExamples' contains small Clean programs.
+The directory contains a Makefile to compile the examples.
 
-Additional information about Clean is can be found on the website:
+General Info
+============
+
+Additional information about Clean can be found on the website:
 
   http://clean.cs.ru.nl
 
 Bug reports, questions and suggestions are welcome. Please send them to:
 
-  mailto:clean@cs.ru.nl
+	mailto:clean@cs.ru.nl
+
+Versions of Clean are available for several platforms.