Valve burst onto the gaming scene with the original Half-Life in 1998, but things could have been very different. At the same time the studio was building its influential first-person epic, it was also working on a story-driven, third-person massively multiplayer game called Prospero. However, that game was ultimately scrapped as resources shifted to Half-Life. "Half-Life proved to be an irresistible force," writer Marc Laidlaw said back in 2003. "The Prospero team was soon absorbed."
Valve Time has put together an excellent summary of what little we know about the cancelled game, along with some brand-new insight thanks to recently unearthed screenshots of the game. Unsurprisingly for a Valve product, Prospero was an incredibly ambitious project, that was to feature some ahead-of-its time features like friends lists and user-made maps. While the game will likely never end up being made, many of those features made it into what turned out to be Valve's biggest release ever: its Steam digital distribution platform.