An ambitious international modding team called Dezowave (opens in new tab) has taken on the challenge of expanding upon GSC's STALKER with the intention of restoring the bleak survival-horror shooter to an earlier, far more open design that GSC had originally planned during the game's development. The project is called STALKER Lost Alpha (opens in new tab) , and it's churned in the reactor core long enough for numerous screenshots and videos to emerge tracking its progress.
All of STALKER's signature elements show up in Lost Alpha including horrifically mutated creatures, rusted machinery, and grizzled Russians huddling around barrel fires. Dezowave also hopes to restore cut content such as reactor blowouts and additional factions, as well as create new assets of its own such as weapons and new zones to expire in.
You can check out a video of the work-in-progress mod below, and a lengthy FAQ (opens in new tab) explains the intricacies of Lost Alpha's considerable undertaking. Best question/answer: "Will we be able to kill crows? Yes."