Forum means two things and both are useful. It’s a discussion venue, in the online community sense, and it’s an event format, the kind of gathering that sits between a conference and a roundtable.
The event reading is the more commercial one. Technology forums are run by industry associations, research bodies, and media companies, usually aimed at senior audiences and sponsored accordingly. Having the category name as the address is a strong position for a recurring event.
The community reading suits a discussion platform, a professional network, or a Q&A resource. Technical communities remain some of the most valuable properties on the web because they generate content indefinitely and their participants are hard to reach elsewhere.
The .net is well matched to both. It reads as a network, which a forum is, and the audience arrives through links and search rather than by guessing.
Two words, no hyphen, plain meaning, listed now.
Offers welcome.