SpeexComm is a Speex-based, multi-platform voice communication engine meant mainly for gaming. Written in C99, the engine itself depends only on libc, but ALSA and Speex libraries are recommended for audio input/output and voice encoding/decoding. The engine is accompanied by some reference UIs.
AVChat is audio and video chat software based on Flash Communication Server with an easy to use interface. It supports real time audio/video communication with bandwidth control and automatic webcam and microphone detection, enhanced text chat with a language filter and bold/italic/color options, a users list with genre/camera/admin icons, private and public rooms, an admin section with log review and ban/kick by IP, a nick filter, and support for free and premium users. A PHP file is used for configuration options. Flash Communication Server is used for the text/audio/video streams.
Skype uses P2P (peer-to-peer) technology to provide voice- and video-based communication with other Internet users. The technology is extremely advanced, but easy to use. It features excellent sound quality, end-to-end encryption, and automatic negotiation of firewalls or routers. Among major features are SkypeOut and SkypeIn, adding the possibility to make low-cost calls to land line phones and having a fixed number to be able to receive calls from land line phones.
GYach Enhanced is a feature-rich, improved version of the original Gyach. It is the first Yahoo! client for Linux with voice chat capabilities. It offers almost all of the features you would expect to find in the official Windows Yahoo! client. The program offers support for chat, conferences, buddy lists, and My Yahoo content. In addition, Gyach Enhanced offers many features not available in the official Yahoo! clients for Windows, Mac, and Linux. Webcam support is under development and planned for the future. Unlike the original Gyach, GYach Enhanced is designed for Linux only.
Intercom is a flexible voice communication utility for Unix systems. It supports the standard audio compression codecs such as GSM, G.711, and G.72x as well as audio encryption. Intercom was designed mostly for high-speed InterNet connections which are able to provide high quality audio. However, it also works on lower bandwidth connections such as dialup if so configured.
The Two Dimensional Spatialization of Sound package takes a single monaural sound signal and processes it to create a binaural signal that places the source of the sound at a selectable arbitrary place around the listener. The package makes use of a set of HRTF Measurements of a KEMAR Dummy-Head Model created by Bill Gardner and Keith Martin of the MIT Media Lab. The sound spatialization software is ANSI C, and can be ported to any platform which will support the sound I/O requirements. The package also includes an FFT written in well-structured C.