Humans vs. Zombies is a popular live-action persistent game of moderated tag, popularly played on college campuses. I have had the pleasure of participating in the game at Mizzou the last five or six semesters. The game has an “engine” component where players receive an automatically generated code and can report tags (ie., codes) through the engine.
Originally the moderator team at Mizzou used the Dormwire engine but quickly changed over to the official HvZSource source in the second semester the game was played. This held for two semesters before the cumbersome and manual nature of the engine caused me to write my own (subtly named KnoopVsZombies). The site is currently hosted at http://www.muzombies.org and has successfully ran two semester-games.
The engine offers several enhancements over the official engine. Namely,
Update: This project is now available on Github!