If the history of Dwarf Fortress interests you, I recommend you check out the history of roguelike games (probably the nerdiest of all my passions.) Dungeon Crawl: Stone Soup, for example, is a beautiful illustration of applying open source software development tenets to a massive game, as dozens of contributors have continuously evolved and enhanced it over time (and its massively fun to boot.)
Speaking of the history of roguelikes, I've been pretty impressed by Nicolas Casalini, aka Darkgod. I'm not sure exactly how long he's been involved in the scene, but he's been developing since at least Pernband back in the late 90s.
His Tome2, in the early part of the last decade, was arguably the pinnacle of old-school band style roguelikes (as opposed to the hack style popularized by nethack, or more modern, user-friendly ones that have been cropping up the past couple years). The current Tales of Maj'Eyal is one of the most polished, engaging roguelikes I've come across.
