My online Planescape chronicle has been running since 2005. With this game, I have hoped to unfold the richly-detailed fantasy setting of the Planescape multiverse for anyone interested to explore. Toward this end, I've included a large freeform section where players can interact freely, write their own scenes, and play at their own respective paces.
In addition to the roleplaying possibilities in freeform, I run various plot arcs in which players can choose to participate -- most of them in the form of excursions across one or more universes of belief made solid. I'll also be scheming up scenes to run in freeform to make PCs' lives a little more interesting.
Players are also welcome to start up their own plot arcs, which I will gladly run (and the more PCs you manage to bring with you, the greater the rewards -- and survival rate -- for all involved). Low on cash and feel like a treasure hunt? Set off for the Astral Plane to explore the corpses of long-dead gods. Prefer a bit of hack and slash? Glorious battle awaits on Ysgard, standing armies on Acheron are always looking for mercenaries, and a war of unspeakable horrors rages across the hells. Up for some political intrigue instead? Propose or lobby for legislation in the Hall of Speakers. Join the cult of an Abyssal Lord. Gather your own personal mercenary army, or found a temple or cabal. Or do any of the millions of other things you may have already imagined.
For those who know the setting, canon is as normal up to the "beginning" of the PS product line (Hashkar's 127th year), but has progressed differently since then (we're currently in Hashkar 130, still no Modron March or Faction War). No familiarity or experience with the setting is necessary; I have a short primer on the site to help with a basic understanding, and I'm more than happy to give anyone a hand and take time to answer questions.