Few commercial developers make the source code for their games available to the playing public for obvious reasons. However, for developer Running With Scissors and it's 20-year old game Postal, those reasons aren't so relevant. So, in the spirit of, uh, curiosity, the company has uploaded the title's source, allowing anyone to take a peek.
Towards the end of December last year, Postal developer Running with Scissors decided to open source the first Postal game. For anyone curious about the game's inner workings — and equipped with an understanding on C++ — you can check out the entire thing on BitBucket.
From the developer's announcement post:
Everyone now has 'under the hood' access, to see what makes POSTAL tick, and anyone with the time and skills can now tweak/change/update/modify anything in the game at all! And hey, if anyone feels the urge to port the game to other platforms (The Dreamcast, for example *wink* *wink*), then they absolutely can!
Understandably, the source is licensed under GPL2, which means while you could cook something up out of the code and sell it, you'd have to include the source code with your changes along with the product.
Eventually, we might see a few projects pop up using Postal as a base (much like the various Doom and Quake-based shenanigans out there), but for the most part, I think it'll serve as an educational experience.