Hello all,
I'd be curious to know, if anyone here has tried--or even heard of--the "RPG," De Profundis. It's a letter writing game in which the "players" assume the roles of characters in a Lovecraftian psycho-horror scenario. It's (almost?) entirely rule-less and based upon improvisation. Certainly, not the kind of thing we typically talk about here but I think that it's of interest because ... well, it's ideally played by mail (although later editions do discuss email and blogs).
Here's the RPGGeek entry:
There have been two English-language editions, so far.