A new mod is in the works for STALKER: Shadow of Chernobyl. Developed by a team named Dezowave and titled STALKER: Lost Alpha, it restores much of the content cut from the cult classic (including factions), and brings back the more open world design present before realistic financial projections came into play.
The team is also adding its own maps and weapons which I'm not entirely about, but who knows, it could be great. If you want to breathe new life into the game but have it remain completely faithful, be sure to check out STALKER Complete if you haven't already.
The project isn't yet available for download, but you can check out its current progress in the trailer below, and read up on the finer details with the FAQ.