One of the new open-source projects to emerge in the past month that's based upon the original Jedi Academy source-code is OpenJK. As a Phoronix reader wrote in this morning about OpenJK, "Immediately afterwards, the OpenJK project was started by some dedicated members of the Jedi Academy modding community and is still going strong. Within 10 days they had ported JKA to Linux and OS X with SDL2. The project makes use of many improvements that were made over the years by these people for other modding projects. Currently, OpenJK is not a separate game from JK2 or JKA."
Other changes to the OpenJK code-base over the original Jedi Academy is support for compiling using LLVM's Clang compiler, various fixes, improved extension detection, and much more. The project has generally been getting multiple commits on a daily basis.
With this simply being the open-source game engine, the Jedi Academy game assets are required (the game is still available for purchase) to play the actual game.