As far as I can tell, the 3rd party dependancies required to compile skycheckers are the following:
OpenGL and GLUT are linked as well, and Cocoa is linked on OS X.
Windows uses to the .dll files, Linux uses to the .a files, OS X uses the .framework files in the repository.
Linux has a linux-loader too that sets the environmental path to dynamic libraries before running the game executable.
Linux support has only been tested on Ubuntu. OS X has been tested on Tiger and above I think, and Windows has been tested on XP and above.
OS X project has a Xcode file. Windows project a DevC++ file. Linux has traditional Makefiles.