diff --git a/.gitignore b/.gitignore
index 16c8ed7..d493eb1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,3 +8,4 @@
 /boids_main
 /libboids.so
 /game.fasl
+/writeimage
diff --git a/ECL-INSTALL b/ECL-INSTALL
new file mode 100644
index 0000000..261fffb
--- /dev/null
+++ b/ECL-INSTALL
@@ -0,0 +1,270 @@
+You will find detailed installation instructions in the ECL manual
+       https://common-lisp.net/project/ecl/static/manual/Building-ECL.html
+If you do not have access to the online version, follow the following recipies.
+
+* Unix and similar platforms.
+1. Type
+   ./configure --help
+   to get a list of the flags with which ECL can be configured.
+2. Enter
+   ./configure ...
+   where "..." is the set of flags you have chosen.
+3. Use "make" followed by "make install" to build and install ECL.
+
+* Windows with Visual Studio C++ 2008
+1. Open the Visual Studio x86 or x64 native tools command prompt
+2. Enter the msvc directory
+3. Read the file Makefile to find the configuration options. They
+   typically have the form ECL_UNICODE=1, ECL_THREADS=1, etc
+4. Enter
+   nmake ...
+   followed by zero or more of those options
+5. Use "nmake install" to create a directory called "package" with ECL in it.
+6. Move that directory wherever you need.
+
+* Cross-compile for the android platform (from the UNIX machine)
+1. Build the host ECL
+   #+BEGIN_SRC shell-script
+     # C99 complex numbers are not fully supported on Android
+     ./configure ABI=32 CFLAGS="-m32 -g -O2" LDFLAGS="-m32 -g -O2"\
+                 --prefix=`pwd`/ecl-android-host --disable-c99complex
+     make -j9
+     make install
+     rm -r build
+     export ECL_TO_RUN=`pwd`/ecl-android-host/bin/ecl
+   #+END_SRC
+2. Configure the toolchain (requires android-ndk version 15 or higher, known to work with version 17c)
+   and export the necessary paths:
+   #+BEGIN_SRC shell-script
+     export NDK_PATH=/opt/android-ndk
+     export ANDROID_API=23
+     export TOOLCHAIN_PATH=`pwd`/android-toolchain
+     ${NDK_PATH}/build/tools/make_standalone_toolchain.py --arch arm --install-dir ${TOOLCHAIN_PATH} --api ${ANDROID_API}
+     export SYSROOT=${TOOLCHAIN_PATH}/sysroot
+     export PATH=${TOOLCHAIN_PATH}/bin:$PATH
+  #+END_SRC
+3. Build and install the target library
+   #+BEGIN_SRC shell-script
+     # boehm GC is not compatible with ld.gold linker, force use of ld.bfd
+     export LDFLAGS="--sysroot=${SYSROOT} -D__ANDROID_API__=${ANDROID_API} -fuse-ld=bfd"
+     export CPPFLAGS="--sysroot=${SYSROOT} -D__ANDROID_API__=${ANDROID_API} -isystem ${SYSROOT}/usr/include/arm-linux-androideabi"
+     export CC=arm-linux-androideabi-clang
+     ./configure --host=arm-linux-androideabi \
+                 --prefix=`pwd`/ecl-android \
+                 --disable-c99complex \
+                 --with-cross-config=`pwd`/src/util/android-arm.cross_config
+     make -j9
+     make install
+   #+END_SRC
+4. Library and assets in the ecl-android directory are ready to run on
+   the Android system.
+
+** Building ecl-android on Darwin (OSX)
+If your host platform is darwin, then the host compiler should be
+built with the Apple's GCC (not the GCC from Macports). Using the
+MacPort command:
+#+BEGIN_SRC shell-script
+  sudo port select --set gcc none
+#+END_SRC
+
+Hint provided by Pascal J. Bourguignon.
+
+
+* Cross-compile for the iOS platform (needs Xcode 11 or higher)
+1. Build the host ECL
+   #+BEGIN_SRC shell-script
+     ./configure CFLAGS="-DECL_C_COMPATIBLE_VARIADIC_DISPATCH" --prefix=`pwd`/ecl-iOS-host --disable-c99complex
+     make -j9
+     make install
+     rm -r build
+     export ECL_TO_RUN=`pwd`/ecl-iOS-host/bin/ecl
+   #+END_SRC
+2. Configure the toolchain
+   #+BEGIN_SRC shell-script
+     export IOS_VERSION_MIN="8.0"
+     export IOS_SDK_DIR="`xcode-select --print-path`/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/"
+
+     export CC="clang"
+     export CXX="clang++"
+
+     export CFLAGS="-arch arm64 -miphoneos-version-min=${IOS_VERSION_MIN} -isysroot ${IOS_SDK_DIR}"
+     export CFLAGS="$CFLAGS -pipe -Wno-trigraphs -Wreturn-type -Wunused-variable"
+     export CFLAGS="$CFLAGS -fpascal-strings -fasm-blocks -fmessage-length=0 -fvisibility=hidden"
+     export CFLAGS="$CFLAGS -O2 -DNO_ASM"
+
+     export LD="ld"
+     export LDFLAGS="-arch arm64 -pipe -std=c99 -gdwarf-2 -isysroot ${IOS_SDK_DIR}"
+     export LIBS="-framework Foundation"
+   #+END_SRC
+3. Build and install the target library
+   #+BEGIN_SRC shell-script
+     export CFLAGS="$CFLAGS -DGC_DISABLE_INCREMENTAL -DECL_RWLOCK"
+     export CXXFLAGS="$CFLAGS"
+     ./configure --host=aarch64-apple-darwin \
+                 --prefix=`pwd`/ecl-iOS \
+                 --disable-c99complex \
+                 --disable-shared \
+                 --with-cross-config=`pwd`/src/util/iOS-arm64.cross_config
+     make -j9
+     make install
+   #+END_SRC
+4. Library and assets in the ecl-iOS directory are ready to run on
+   the iOS system.
+
+* Cross-compile for the WASM platform (via emscripten)
+
+Emscripten target is a little fickle so keep in mind that:
+
+- shared libraries are supported but come with some drawbacks (e.g.
+  increased code size if used together with -sASYNCIFY), therefore the
+  build instructions default to disable-shared
+
+- disable-tcp is needed, because accept can't be found (lack of
+  -lsockets or something in this spirit?)
+
+- select for interactive streams does not work, because reading operations are
+  blocking (as they should be!), so there is no EOF returned -- clear-input will
+  hang without a proper file-cnt
+
+- to build emscripten you need to use their SDK that provides the toolchain, and
+  set the environment variable EMSDK_PATH
+
+- for the garbage collector to be able to identify roots on the stack,
+  you need to pass the -sBINARYEN_EXTRA_PASSES=--spill-pointers option
+  to the linker for all of your code that might store pointer on the
+  stack (for instance when embedding ECL)
+
+- the optimization level -O0 is used because higher optimization
+  levels seem to interfere with the binaryen options needed to get the
+  garbage collector to work correctly and tend slow down the program
+  (might be worth experimenting with the optimization options)
+
+1. Build the host ECL
+
+#+begin_src shell-script
+  ./configure ABI=32 CFLAGS="-m32 -g -O2 -DECL_C_COMPATIBLE_VARIADIC_DISPATCH" LDFLAGS="-m32 -g -O2" \
+              --prefix=`pwd`/ecl-emscripten-host --disable-threads
+
+  make -j16 && make install
+  rm -rf build/
+#+end_src
+
+2. Configure the toolchain
+
+Install the Emscripten SDK using the official instructions:
+
+        https://emscripten.org/docs/getting_started/downloads.html
+
+These build instructions were tested against ~emsdk 3.1.41~. If things doesn't
+work try that version instead of ~latest~.
+
+After that activate the toolchain and configure build flags:
+
+#+begin_src shell-script
+  source ${EMSDK_PATH}/emsdk_env.sh
+  export ECL_TO_RUN=`pwd`/ecl-emscripten-host/bin/ecl
+  # You may customize various emscripten flags here, i.e:
+  # export LDFLAGS="-sASYNCIFY=1"
+#+end_src
+
+3. Build the core environment and install it
+
+#+begin_src shell-script
+  emconfigure ./configure \
+              --host=wasm32-unknown-emscripten \
+              --build=x86_64-pc-linux-gnu \
+              --with-cross-config=`pwd`/src/util/wasm32-unknown-emscripten.cross_config \
+              --prefix=`pwd`/ecl-emscripten \
+              --disable-shared \
+              --with-tcp=no \
+              --with-cmp=no
+
+  emmake make && emmake make install
+
+  # some files need to be copied manually
+  cp build/bin/ecl.js build/bin/ecl.wasm ecl-emscripten/
+#+end_src
+
+4. ECL may be hosted on a web page. Assuming that you have quicklisp installed:
+
+#+begin_src shell-script
+  export WEBSERVER=`pwd`/src/util/webserver.lisp
+  pushd ecl-emscripten/
+  lisp --load $WEBSERVER
+  # After the server is loaded run:
+  # firefox localhost:8888/ecl.html
+  popd
+#+end_src
+
+If the output does not show on the webpage then open the javascript console.
+This is a default html website produced by emscripten.
+
+5. Build an external program linked against libecl.a
+
+The default stack size proposed by emscripten is 64KB. This is too little for
+ECL, so when you build a program that is linked against libecl.a, then it is
+imoprtant to specify a different size. For example:
+
+#+begin_src shell-script
+  emcc program.c -sSTACK_SIZE=1048576 lib/*.a -I./include -o program.o
+#+end_src
+
+* Build using Cosmopolitan toolchain (experimental)
+
+Binaries built with cosmopolitan toolchain can be executed on numerous platforms
+without changes. An inititial ECL port has been completed.
+
+1. Download cosmopolitan toolchain and activate it
+
+Instructions for downloading the toolchain are available in its [[https://github.com/jart/cosmopolitan/blob/master/README.md ][repository]].
+For example:
+
+#+begin_src sh
+  mkdir cosmocc
+  pushd cosmocc
+  curl -o https://cosmo.zip/pub/cosmocc/cosmocc.zip
+  unzip *zip
+  bin/make --version # sanity test
+  export PATH="`pwd`/bin:${PATH}"
+  export CC=x86_64-unknown-cosmo-cc
+  export CXX=x86_64-unknown-cosmo-c++
+  popd
+#+end_src
+
+2. Build ECL
+
+#+begin_src sh
+  ./configure --disable-shared --prefix=/tmp/cosmo-cl
+  make -j15
+  make install
+  # make check
+#+end_src
+
+- The platform is reported in *FEATURES* as :COSMO and as :LINUX
+- make check will fail because libc segfaults when using fenv.h
+
+This platform is not upstreamed yet in libgc, so it may be necessary to add the
+following code to the file gcconfig.h:
+
+#+begin_src c
+# if defined(__COSMOPOLITAN__)
+#   if defined(__x86_64__)
+#     define mach_type_known
+#     define X86_64
+#     define LINUX // optional?
+#   elif defined(__aarch64__)
+#     define mach_type_known
+#     define AARCH64
+#     define LINUX // optional?
+#   endif
+# endif
+#+end_src
+
+For details see: https://github.com/jart/cosmopolitan/issues/939.
+
+Cosmopolitan condition variables can't be used with mutexes that are not
+initialized as PTHREAD_MUTEX_NORMAL. That means that recursive locks and
+deterministic deadlock detection are not supported on this platform.
+
+Moreover floating point exception handling is not working and it is libc issue
+that manifests itself with segfaults.
diff --git a/README.org b/README.org
new file mode 100644
index 0000000..5ab39d9
--- /dev/null
+++ b/README.org
@@ -0,0 +1,12 @@
+
+#+begin_src shell
+
+gcc -lecl ecl_test.c  -o test-game libtest-game.a
+#+end_src
+
+#+begin_src lisp
+(uiop:getcwd)
+(uiop:chdir "Development/tinyswords/")
+(compile-file "game.lisp" :system-p t)
+(c:build-static-library "test-game" :lisp-files '("game.o") :init-name "game")
+#+end_src
diff --git a/ecl_test.c b/ecl_test.c
new file mode 100644
index 0000000..0c2a39b
--- /dev/null
+++ b/ecl_test.c
@@ -0,0 +1,15 @@
+#include <ecl/ecl.h>
+
+extern void game(cl_object cblock);
+
+int main(int argc, char **argv)
+{
+    /* setup the lisp runtime */
+    cl_boot(argc, argv);
+    /* call the init function via read_VV */
+    read_VV(OBJNULL, game);
+    /* ... */
+    /* shutdown the lisp runtime */
+    cl_shutdown();
+    return 0;
+}
diff --git a/game.lisp b/game.lisp
index d400e1d..d8bd840 100644
--- a/game.lisp
+++ b/game.lisp
@@ -1,3 +1,5 @@
+(load "~/quicklisp/setup.lisp")
+
 (eval-when (:compile-toplevel :load-toplevel :execute)
   (ql:quickload :cl-raylib))
 
@@ -66,7 +68,7 @@
                        :white)
   (rl:draw-fps 10 5))
 
-(defun main ()
+(defun game ()
   (let* ((screen-width 900)
          (screen-height 500))
     (rl:with-window (screen-width screen-height "RTS")
@@ -80,4 +82,4 @@
       (loop for value being the hash-values of (game-state-textures *game-state*)
             do (rl:unload-texture value)))))
 
-(main)
+(game)