RAT is an RTP audio conferencing and streaming application that allows users to particpate in point-to-point and multi-point audio conferences over the Internet. Developing features include multiple sampling rates, mono/stereo, loss concealment, and IPv4/IPv6 support, and both versions feature encryption and run on a range of platforms.
Ekiga (formely known as GnomeMeeting) is a soft phone, video conferencing, and instant messenger application for use over the Internet. It supports HD sound quality and video up to DVD size and quality. It is interoperable with many other standards compliant software, hardware, and service providers as it uses both of the major telephony standards, SIP and H.323.
SER or SIP Express Router is a very fast and flexible SIP (RFC3261) server. It can handle thousands of calls per second on low-budget hadware. A C shell-like scripting language provides full control over the server's behavior. Its modular architecture allows only required functionality to be loaded. The following modules are available: accounting, digest authentication, CPL scripts, ENUM support, instant messaging, MySQL support, PostgreSQL support, a presence agent, Radius authentication and accounting, Diameter authentication, record routing, an SMS gateway, a Jabber gateway, NAT traversal support transaction module, a registrar, and user location.
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.
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.
KDX is a powerful cross-platform BBS-style encrypted Internet communications system that provides messaging, news, file and folder transfer, voice chat (Internet Telephone), text chat, remote access, trackers, and more. It uses strong encryption to protect communications for security and privacy. It is useful for groups that need to collaborate on a project via the Internet. It is also very useful for remote administration of a computer. It uses a client/server architecture.
Gizmo Project is a program that uses advanced VoIP technology to allow you to talk with your friends around the world. Gizmo Project uses your Internet connection to make calls to people using other computers. It is simple, and allows you to talk clearly and for as long as you want.