OpenJKDF2 is an open-source re-implementation of “Jedi Knight: Dark Forces II” (JKDF2).
OpenJKDF2 removes the hassle of rendering and input compatibility shims, while also
providing in-app guided installation steps, cross-platform multiplayer, and a host
of graphical (and other) improvements:

Jedi Knight™ Dark Forces II is Copyright © Lucasfilm Ltd. 1997-2009.
An original “Jedi Knight: Dark Forces II” game disk, or original licensed assets from Steam or GOG, are required in order to play OpenJKDF2.