At first the Cosmos Source can look like a daunting thing. This folder structure guide should help you to find what you're looking for.
Tools & 3rd party applications/files required for the building and running of a Cosmos OS
A folder added by Codeplex for some reason...
Various user end documentation for the Cosmos User Kit. Quite badly structured.
A single build script for doing something or other
Dependency .dll's that Cosmos needs
Files needed for the installer including the inno setup file
The first folder full of source and an assortment of used and non-used code
Lots of folders with source in to explain, a seperate page is linked above.
A single TeamProject.config file
Things for XSharp (the cosmos compiler language) but not all the source
(C) Cosmos Project 2007-2013