KMuddy is a MUD client powered by KDE. It aims to be the most powerful, fast, feature-rich and easy to use MUD client. The current version already offers many features such as powerful external scripting (which supports very many languages such as Python, Perl, Lua, and C/C++) and its own internal scripting. It has split-screen scrolling, command history, an auto-mapper, buttons, gauges, logging (both in plain text and HTML), multiple connections, regex support (on both aliases and triggers), and much more.
TinyMUX is a text-based game server in the MUSH family. It is a platform that allows several thousand players to connect to a single text-driven environment, and interact with each other and with the environment (which is maintained in a database). The rich programming environment can be used to build almost anything, limited only by the developer's imagination.
Gamma Low is a multi-player RTS in which two opposing teams of light-based lifeforms fight for the dominance over a cellular system in match style. The players in each team are split into different classes (strategist, tacticians, workers/attackers/supporters) and have to conquer all enemy cells in order to win. They do so by harvesting resources, building structures, researching technologies, creating deadly viruses, and fighting harsh battles.