AA-lib is a low level gfx library just as many other libraries are. The main difference is that AA-lib does not require graphics device. In fact, there is no graphical output possible. AA-lib replaces those old-fashioned output methods with a powerful ASCII art renderer. The API is designed to be similar to other graphics libraries.
Allegro is a multi-platform game library for C/C++ developers that provides many functions for graphics, sounds, player input (keyboard, mouse, and joystick), and timers. It also provides fixed and floating point mathematical functions, 3D functions, file management functions, compressed datafile, and a GUI.
BZFlag is a 3D, multiplayer, tank battle zone, capture the flag game that pits players against each other in a networked environment. It runs on Windows 95/98/NT/2000, Linux, MacOS 10.x, Irix, Solaris, and others. An OpenGL accelerator is highly recommended, but it is playable with 3D in software.
CFL (Compressed File Library) is meant for the save-files used by games, and other sorts of data files. Its features include pluggable class factories, easy CFL file creation at runtime, and the ability to have multiple separate CFL objects in memory at the same time. The package also includes a CFL testing tool to make it easier to port the library and to create additional plug-in compressors, preprocessors, and ciphers. It also includes a makecfl utility, which makes it easy to create ini files.
DeskNow WebMessenger is a Jabber/XMPP secure instant messaging server that includes a Web-based IM client. It can be accessed transparently across firewalls, proxies, and NAT, and supports 128-bit SSL encryption. Other features include the support for unlimited virtual domains, a Web-based administration console, and the ability to send broadcast messages and alerts to all users. It is compatible with the most popular Jabber clients, and can run on any OS.
FFmpeg is a tool for converting audio, video, and subtitles. It includes libavcodec, the leading open source codec library. It also includes libavformat (implementing muxers and demuxers), libswscale (for very fast video scaling), and libavfilter (an advanced video filter system supporting arbitrary filter graphs), and libavutil (a utility library intended to supplement libc). A simple multimedia player is included too. An experimental streaming server for live broadcasts is also included.
FrobTADS is a complete rewrite of the Unix console-version of TADS ("Text Adventure Development System"). It uses curses (or ncurses) and provides an interpreter to play games developed with TADS as well as the TADS 2 and 3 development tools. It adds support for a number of relatively recent user interface features including full support for text and background colors, TADS 3 banner windows, and timed input. It's also much more portable and more easily maintainable, as it's built to modern Unix standards.