The fortbattle player replays a fortbattle of the browser game "The West" (http://www.the-west.net). It displays the battle like the ingame flash player, but you can control the speed, skip rounds and see some statistics. Ingame use req. GreaseMonk
Free MMORPG Engine. Develop and host graphical browser-based games.
DimensioneX is a free Massive Multiplayer Game Engine.
It lets you develop and then run or host browser-based, graphical multiplayer games. The users will play games simply via their browser.
DimensioneX runs on any Java-enabled web server (eg. Tomcat)
Ruin is a 2.5D Java game world that can run from a browser. It's like a 3D MUD. The game looks similar to Doom or Heretic. View the home page for a demo (http://ruinworld.sourceforge.net).
Eternal Warfare is turn driven, browser based game. It will have multiple realms to play through and eventually travel back to. Development will be focused mainly on community driven systems and will also create a flexible character development system.