http://www.pcgamer.com/half-life-caged-is-a-free-mod-from-a-valve-alumnus/

Though the chances of us ever playing a new, official Half-Life game again are slim, Valve’s seminal series still has its hooks in us, as evidenced by the latest issue of PC Gamer. Ex-Valve employees are similarly plagued by visions of Gordon Freeman, the latest being Cayle George, whose free Half-Life 2 mod is now available on Steam. 

Half-Life: C.A.G.E.D. follows hot on the heels of the game jam inspired by the tweaked Episode 3 story synopsis from Marc Laidlaw, though it has nothing to do with Episode 3, instead being a prison escape mod, full of shooting and environmental puzzles.