File format wiki
I worked in video games reverse engineering for several years, so I'll take the occasion to quote a recent tweet from a friend/colleague of mine:> At HandmadeCon @mike_acton brought up the game data format problem.  I've reverse engineered hundreds of proprietary formats from games, and he's right that all I would need to make things simple is a basic description of the file data. Just struct declarations are enough.
No encryption has stopped me, I always find the data I need, and your data all has the same general architecture, so there's no reason a game developer should be afraid of the public knowing how their game's data is laid out. This zeitgeist of closely guarding that information is doing you more harm than good — moddability is a key feature of many successful games, and all modders want is docs.--There's a lot of other industries that could stand to learn from this. Reinventing the wheel sucks. Doing your own, proprietary thing in your corner, taking on extra maintenance work, extra work to modify existing tools to make them compatible with your own image/archive/whatever format... it all sucks and nobody wins.