Jazz Jackrabbit 2 Plus (JJ2+) adds countless features and bug fixes to both Single Player and Multiplayer gameplay within JJ2, and is used almost universally by most serious players. It has much better network code than the original game, adding console commands to online games, fixing most major game-crashing errors and connection problems, allowing permitted clients to log in as "remote administrators" in someone else's server and control the gameplay, and adding several new multiplayer gamemodes. It additionally fixes or enhances many of the events in the game, and allows level designers far more power than in regular JJ2 through the addition of an easy-to-use scripting language. JJ2+ takes everything great about JJ2 and adds so much more on top of it; it is truly a must-download. JJ2+ is distributed under the MIT license.
Plus offers control over many aspects of the basic Jazz Jackrabbit 2 gameplay experience. Here, the player must transport two giant glowing purple gems to the end of the level in order to receive a reward. The time limit in the upper right corner, the modified score counter in the upper left, the unearthly palette, aspects of the level layout, and of course the gems themselves are all products of JJ2+ and its AngelScript support.
Sweet!