Quake Live runs on a slightly updated version of the id Tech 3 engine, but the focus remains on usability rather than major graphical upgrades. Among other usability changes, Quake Live has a new, more streamlined HUD. The program is a modified version of Quake III Gold and executed as compiled code on the user's processor. The user downloads the game in the background as a part of the registration process and interacts with the program either through a browser plugin that can be embedded on the webpage or as fullscreen. Updates to the game are continually released and automatically installed as the user logs in.
The browser plugin does not make use of Flash to play the game.[2]
Quake Live registration of a user account is available on the Quake Live website for free to anyone wishing to play. Currently, only Internet Explorer 7+, Mozilla Firefox 2+, and Safari 3+ web browers running in either Windows XP, Windows Vista, Mac OS X 10.4+, and Linux are supported.