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.
Early beta versions of Jazz 2 had a somewhat different assortment of weapons than the final version, including the Fireball Gun, which was replaced with Pepper Spray before the final release. JJ2+ reintroduces the fireball gun, letting level designers or server hosts choose which of the two guns they want available, and makes it more useful in the process by upping its speed and giving it the power to destroy large numbers of destructable blocks at a time.