Update: if you're having trouble getting in (it's open to all, but there might be a wait), Tiny Speck has set up a "fast pass" site for Joystiq readers here.

Glitch, the cute browser MMO set inside the minds of giant monsters, is officially opening up to the public today at 10AM PDT after a long beta period. The game is the work of Tiny Speck, a new company formed by Stewart Butterfield, Cal Henderson, Eric Costello, and Serguei Mourachov, four co-founders of Flickr. It's a free-to-play game with subscription and virtual currency options, both used for avatar customization items.

Speaking to me in a phone interview yesterday, Butterfield claimed that the game is playable in a casual style, but also accommodates players interested in a more intense experience. "We wanted to have enough depth to capture the imaginations of people who want to go deep," he said. "There are 1000-plus items and 90 skills."

Glitch has potential for emergent gameplay, which he compared to Eve Online, though he was quick to note that it's not as combat-oriented as Eve and more fun to actually play. For example, he related an anecdote from the beta, about players creatively using a "notes" system. "Early on, some of the richer players started a bank, with an alternative currency that was based on notes," Butterfield said. "They just guaranteed the notes with their supply of in-game currency based on the timestamp and the person who created it."