Myst Online: Uru Live -- the online installment in the classic Myst series -- has had a very troubled journey throughout the years, but it looks like developer/publisher Cyan Worlds is finally ready to give it the backing it deserves, quite possibly thanks to its big Good Old Games sales. Just now, they've taken the "first step" in bringing the game open source: starting up a server for it, and re-opening all of the Ages and goodies.
Myst Online is entirely free, however Cyan has put a donation button up. No pressure, though -- quoth the official website:
Five or ten bucks would go a long way toward helping pay the server and people bills. (No promises, but we’re trying to figure out a way to show our appreciation to supporters by giving you a little something extra in MO:ULagain.) But don’t feel obligated—we’re just glad to have the cavern open once again.
Thanks for helping keep Uru alive!
You can find all the details and the sign-up page via the link below, though be warned it's been getting hammered today, so things could be slow for awhile.