Star Wars: Dark Forces, the first Star Wars FPS and predecessor to the Jedi Knight series, has finally gotten the ZDoom (opens in new tab) treatment. Developers luciusDXL, winterheart, and gilmorem560 have released the 1.0 build of the Force Engine (opens in new tab), an open source reverse engineering of Dark Forces (and soon, its lesser known cousin, Outlaws) that lets you play it with modern conveniences and at high resolution.
Released in 1995, Dark Forces is firmly of the "Doom Clone" era of first-person shooters. It has that slippery, speedy boomer shooter movement, a great weapon selection, and sprawling, mazelike levels, but it really innovates in its presentation. Dark Forces nails the music, sound effects, and look of Star Wars while also telling a pretty in-depth story about Han Solo-alike Kyle Katarn doing battle with the Imperial Remnant.
These days, Dark Forces is somewhat overshadowed by its sequels in the Jedi Knight series, which see Kyle become a Jedi and engage in what is still the best-feeling lightsaber combat anyone's ever done in a game. Outlaws (opens in new tab), meanwhile, is a western-themed Lucasarts FPS that reuses Dark Forces' original Jedi Engine. This shared DNA will let the less-fondly remembered Outlaws ride Dark Forces' coattails into the 21st century with only a bit of extra effort from the Force Engine team.
In its 1.0 release, the Force Engine lets you play Dark Forces to completion with a highly customizable selection of quality-of-life features like mouse look and high resolution support. The Force Engine also now supports GPU rendering as opposed to the original's archaic software renderer, and features a mod loader for past and future user-made creations. The Force Engine team has indicated that full Outlaws support will come at a later date in the project's 2.0 update.
Installation of both the Force Engine itself and mods is a snap. You'll still need a copy of Dark Forces to start—it's not freely available and included with the source port like Bungie's Marathon is with Aleph One—and you can find it on Steam (opens in new tab) or GOG (opens in new tab) for $6 usually (at the time of writing it's on sale for $2 on GOG!) After downloading the mod, running the Force Engine executable will automatically detect your installation path for the game.
You can just drop any user-made maps or tweaks in the "Mods" directory of the Force Engine, and select which ones to load from an option on the Force Engine's startup screen. I grabbed the fan mission Among the Shadows: Fortress Quadrigon from the DF-21 (opens in new tab) repository of Dark Forces mods and had it up and running in seconds. Like with GZDoom (opens in new tab) or Aleph One (opens in new tab), the Force Engine opens up a whole world of free FPS levels in addition to letting you more comfortably and conveniently play an old classic.