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.
BitchX is the premiere IRC (Internet Relay Chat) client. It originally was a modified version of the popular ircII client, and the features were eventually merged into the EPIC IRC client. The current development is aimed at merging the client back to a current branch of EPIC and bringing compatibility and stability back to the client, while bringing the features that are BitchX into a new client.
KVirc is a Visual Internet Relay Chat Client based on the Qt library. Features include a MDI user interface, drag & drop, built-in scripting language (aliases, popups and events), customizable backgrounds and colours, DCC (chat, send with resume, voice), CTCP functions, mIRC colour support with preview, notify list, online help and configurable logging.
123 Flash Chat Server is a full-featured chat server for high-load Web sites. It features a range of customization options, and can be smoothly integrated with the database of almost all leading CMS or forum systems including Joomla!, phpBB, skadate, and vBulletin. It includes plain text chat and video chat options, and is scalable enough to fit the needs of small business and large enterprises. A free 10-user edition is available. It's based on a Java server and a Flash client, but also has various alternative clients based on technologies such as HTML/AJAX, so it can run on many platforms, including iPhone and iPad. It features avatars, smilies, Flash emotions, voice messages, entering multiple rooms, dynamic skins, loading external avatars and profiles, and a media player. The HTML 5 client significantly improves the chat performance in terms of loading speed, video layout, and user interface.
climm (CLI-based Multi-Messenger) is a portable, small, yet powerful console-based ICQ and XMPP client. It supports password changing, auto-away, creation of new accounts, and other features that makes it a very complete yet simple client. It is able to send and receive messages from the ICQ network, list users that are offline and online (including their online status), search for users by email address, and look up basic (name, UIN, email) information. climm was formerly known as mICQ.
Collaba is a multimedia collaboration and communication server built to provide digital workspaces to virtual educational, corporate, and other communities. It features secure email (Web, POP3/SMTP, crypto, and anti-spam), online forums (Web, RSS, NNTP, and podcast), blogs (Web, RSS, podcast), multimedia chat (text, multimedia panel, etc.), personal and group calendering, address books, bookmarks, an online Web page editor, file services and CMS (Web, WebDAV, FTP, SMB, CIFS, anvi-virus API, and ClamAV support), digital portfolio, dynamic news board, directory access, support for multiple independent communities on one server, Single-Sign-On features (built-in support for LDAP, CAS 2.0, JAAS, SMTP-Auth and more, powerful developer API), full online server management, anti-spam (RBL and filters), anti-virus support, centralized management with LDAP directories, Web publishing of personal, group or general web sites, developer APIs, and much more.