I have a regular group that I usually play one-shots or short campaigns with on the weekends. If I find something that interests me I'll usually post it in our discord to see if anyone else wants to give it try. Sometimes we even play it!
Viewing post in Keeping Track of Games
it's basically Slack or IRC with slightly friendlier UI. Users can create their own servers and those servers can have different text and voice chat channels. Pretty easy to set up and use, but it certainly has its own quirks and idiosyncrasies.
There's an official itch one if you want to see how it's set up.