a multi-platform game library for C/C++ developers that provides many functions for graphics, sounds, player input (keyboard, mouse, and joystick), and timers.
protocol intended for use in networked roleplaying games, and provides a flexible and extensible means of communicating between the components of a game system. The protocol is transport independant, encoding independant and portable.
a game programming library for C/C++ developers distributed freely, supporting the following platforms: DOS, Unix (Linux, FreeBSD, Irix, Solaris, Darwin), Windows, QNX, BeOS and MacOS X. It provides many functions for graphics, sounds, player input, etc..
devoted to game / 3D graphics programming with DirectX / OpenGL using C++. Contains downloadable source code for several small and very specific sample programs that I think will be very helpful to anyone trying to learn both 2D and 3D game programming.