OpenJazz20260301

Play the classic Jazz Jackrabbit games through an independently developed implementation that replaces the original game executable while preserving the familiar platform-action experience. OpenJazz is designed for players who already have the required files from one of the original games, since those game data files are needed to run it.

The program supports data from the CD edition containing all 11 original episodes: episodes 1 through 6, A through C, Christmas Edition, and Holiday Hare ’95. Those files are compatible with OpenJazz, allowing players who previously used only the shareware episodes to access the complete set of content. The difficulty setting can be changed during a game, and the current release also adjusts Jazz’s and enemy health according to difficulty, making higher settings substantially harder.

Version 20260301 fixes tilemask loading problems that made some tiles impassable in levels such as Medivo, and corrects incorrect colors caused by palette handling with SDL3 when scaling is disabled. Most menu screens now center their output and align better on small displays, while the original Jazz resolution is 320×199. A new HUD style can present information like a first-person shooter, with examples including DOOM and Quake.

OpenJazz runs on Windows systems using x64 architecture and is published by AJ Thomson under an open-source license. It suits players revisiting the original games, especially those who have preserved or obtained compatible game data and want to run it through this alternate implementation.