diff --git a/platform/base.cwa b/platform/base.cwa
deleted file mode 100644
index 449cff2..0000000
--- a/platform/base.cwa
+++ /dev/null
@@ -1,3 +0,0 @@
-import "env.memory" memory(2);
-
-export fn tic(time: i32) {}
diff --git a/platform/makefile b/platform/makefile
index fcda944..67b44a1 100644
--- a/platform/makefile
+++ b/platform/makefile
@@ -1,7 +1,4 @@
-all: loader.wasm base.wasm
+all: loader.wasm
 
 loader.wasm: loader.cwa
 	curlywas loader.cwa
-
-base.wasm: base.cwa
-	curlywas base.cwa
diff --git a/site/content/_index.md b/site/content/_index.md
index efbbe01..387a69c 100644
--- a/site/content/_index.md
+++ b/site/content/_index.md
@@ -5,6 +5,70 @@
 
 * [v0.1pre1](v0.1pre1)
 
+## Spec
+
+MicroW8 loads WebAssembly modules with a maximum size of 256kb. You module needs to export
+a function `fn tic(time: i32)` which will be called once per frame.
+After calling `tic` MicroW8 will display the 320x256 8bpp framebuffer located
+at offset 120 in memory.
+
+The memory has to be imported as `"env" "memory"` and has a maximum size of 256kb (4 pages).
+
+Other imports provided by the platform:
+
+* in module `math`:
+* * `fn acos(f32) -> f32`
+* * `fn asin(f32) -> f32`
+* * `fn atan(f32) -> f32`
+* * `fn atan2(f32, f32) -> f32`
+* * `fn cos(f32) -> f32`
+* * `fn exp(f32, f32) -> f32`
+* * `fn log(f32) -> f32`
+* * `fn sin(f32) -> f32`
+* * `fn tan(f32) -> f32`
+* * `fn pow(f32) -> f32`
+
+## `.uw8` format
+
+The first byte of the file specifies the format version:
+
+#### Format version `00`:
+
+This file is simply a standard WebAssembly module
+
+#### Format version `01`:
+
+The rest of this file is the same as a WebAssembly
+module with the 8 byte header removed. This module
+can leave out sections which are then taken from
+a base module provided by MicroW8.
+
+You can generate this base module yourself using
+`uw8-tool`. As a quick summary, it provides all function
+types with up to 5 parameters (i32 or f32) where the
+`f32` parameters always preceed the `i32` parameters.
+Then it includes all imports that MicroW8 provides,
+a function section with a single function of type
+`(i32) -> void` and an export section that exports
+the first function in the file under the name `tic`.
+
+## Tooling
+
+The [Web Assembly Binary Toolkit](https://github.com/WebAssembly/wabt) includes
+a few useful tools, eg. `wat2wasm` to compile the WebAssemby text format to binary
+wasm and `wasm2wat` to disassemble wasm binaries.
+
+If you don't like the look of the `.wat` text format, you might want to take a
+look at [CurlyWas](https://github.com/exoticorn/curlywas), a curly-braces infix
+syntax for WebAssembly.
+
+Once you have a size-efficient `.wasm` file, you can use [uw8-tool](https://github.com/exoticorn/microw8/tree/master/uw8-tool)
+(currently included in the MicroW8 repository) to strip off sections of the
+WebAssembly module that are provided by the MicroW8 platform.
+
+Writing code for MicroW8 in C, Rust, AssemblyScript etc. should absolutely
+possible but no examples are provided, yet.
+
 ## Examples
 
 * [Technotunnel](v0.1pre1#AQrDAQHAAQIBfwp9A0AgAUEAsiABQcACb7JDmhkgQ5MiBCAEIASUIAFBwAJtQYABa7IiBSAFlJKRIgaVIgcgByAAskHQD7KVIgIQAEPNzEw/lCIDlCAHIAeUIAOUIAOUQQGykiADIAOUk5GSIgiUIAOTQQqylCACkiIJqCAFIAaVIAiUQQqylCACkiIKqHMgCEEyspQgBpUiCyACkkEUspSocUEFcbJBArIgC5OUQRaylJeoOgB4IAFBAWoiAUGAgAVIDQALCw==) (199 bytes): A port of my [entry](https://tic80.com/play?cart=1873) in the Outline'21 bytebattle quater final