Offering up the source code fits right in with the bizarre existence of Quadrilateral Cowboy itself, in fact, as it's a cyberpunk puzzler that's all about overseeing a hacking operation while utilizing a 56.6k modem and 256k of RAM. Impressive specs, right?
The code is written in C++, with solution files for Microsoft Visual C++ 2010, and is available in a package that's just 12MB large. The game was created on a modified version of the same engine behind Doom 3 and Quake 4, and if you're interested in putting those tinkering skills to good use, you can grab the source here.
That should satisfy any urges to mess about in the world of tech that arise after a game of Quadrilateral Cowboy.