I figured I would share the basic tools I use to make games and other crap. Gulag for instance was programmed in java, primarily using the LibGDX framework.
For the games graphics, I used aseprite. This is probably the best pixel editing tool I've used Check it out here
For level editing, I used Tiled. It's a bit rough around the edges but it covers pretty much anything you would need for a 2d tile editor. Check it out here