When working on my own, I simply write everything here in the forum while making notepad backups when necessary. I use various syncpads for more collaborative work, and for the purposes of discussion chatzy has proven most convenient. There is also Discord, but most roleplayers utilization of extensions from the main RPG discord limits my own use of it.
On the specific note of collaborative tools, I would like to specifically talk about the use of syncpads, google docs, and actual full-blown wikis for specific roleplays. In my experience, storing all of the information together in one easy-to-edit document or even a series of them combined with realtime chat has the counter-intuitive effect of creating stagnation in the roleplay proper. The problem is not quite that people get too bogged down in too many small details, but that the greater access and freedom to discuss those smaller details tends to lead to plot developments that then drag and eventually die if so much as one party loses interest or has to go inactive for a while. Such documents invite a greeter degree of collaboration from people than might otherwise be advisable given varying degrees of commitment and interest between individuals. For that very reason, I approve more of keeping sheets right here in the forum in a more static format, forcing roleplayers to actually write in the thread in order to convey detail and development rather than just writing about it endlessly in some never-to-be-seen syncpad. I myself am guilty of this - my favorites bar is cluttered with syncpad links from dozens of old roleplays, describing various plots and details of stories which ultimately never saw the light of day.
There are only a few roleplays that ever get big and detailed enough to really benefit from a wiki, and to an extent it can result in the exact same kind of problem as investing too much detail into a syncpad codex. At the same time the, its slightly more rigid and static format means that people still need to go out of their way to talk about everything and various shenanigans elsewhere, which can hopefully lead to more active collaborations (though one should be wary of posters being lured in to endless editing campaigns). Wikis seem to be most useful for organizing large amount of disparate information in a setting with a lot of stuff to sift through - Large Space NRPs where you might want to find out what factions have what things, but do not necessarily want to have to sit down and read through each individual nation sheet all over again.
