Half-Life is 25 years old, and its makers posted a documentary about its development, covering everything from the early days of Valve to the game's genre-defining success. Dave Riller, lead designer, says that when they founded the company, only three people there had even shipped a game.
Check out the Half-Life 25th Anniversary Update, restored content, new multiplayer maps, and a bunch of quality of life updates for the original game at http://half-life.com/halflife25
Bonus: Gabe Newell looks like Santa now. Unbonus: you're not getting HL3 for Christmas.