From what I've seen, "free-form" seems to mean "no rules, no holds barred, bring in whatever you want, do whatever you please." A number of GM-less games I've played in, however, don't really fit that mold. They have rules, certain expectations, restrictions on character types, and all the other things you'll generally see in any moderated game. The only thing they don't have is a GM. Describing these games as "free-form," however, leads to problems, as people try to bring their Assamite/Fenrir Methuselah Abomination into a Changeling game, or try to shoehorn character type from other spheres into a one-sphere game ("Yeah, I know it's a changeling/mortal-only game, but I'm gonna play my Kinfolk Hunter with the mage best buddy, who talks to the Wraith of his great-great-great-grandfather, who was a Gypsy hero!"), which leads to all sorts of problems as we try to explain that in this case, "free-form" does not mean "free-for-all."
I think that games without a GM need another description besides "free-form." I've been using "player-run;" does anyone else have any other ideas?