what prominent technical conference is done entirely or partially using a forum?

back in college we were shown screenshots of forum discussions in some conference of computer scientists, or electrical engineers, or something of that nature. I am not sure if the conference was being held entirely online or else if these were preliminary discussions, and these guys would meet in a physical location subsequently. The only other things that I remember is that this was not a one-off thing (i.e. this conference occurs regularly) and that the forum software being used supported multiple branches within the same thread.

Does anybody here know what that conference might be? Or, perhaps, are there multiple conferences that use forums prominently?

There’s many mailing lists for computer scientists, even ones associated with conferences. One big one is the TYPES mailing list, associated with the TYPES conference (very well known, and probably the most prominent meeting for those interested in type theory on either side of the Atlantic), which started as the conference of the European Union’s TYPES project. It started in 1987.

I’d be surprised if there was a conference that took place entirely online without anybody meeting. That seems to me to subvert the whole point of a conference, and I can’t imagine computer scientists, who place undue prominence on conferences and workshops when compared to other fields of learning, doing this.