I use FPC and Lazarus. For libraries I use OpenGL and OpenAL, as well as Ogg Vorbis for music files. I have my own reader for wave(.wav) files. That's pretty much it. As far as loading images, creating windows, UI and other stuff goes I have written my own code(a lot of code), to depend on as little libraries as possible, though I do use JPEG functionality that comes with FPC (pasjpeg). All headers are included with FPC. My code works on Windows and Linux, though with some lack of functionality under Linux (X11 is a slight pain).