Looking for the best PHP/MySQL Forum SW

Anon

I am looking for the best PHP/MySQL Forum software available. Here are some of my criteria:

1) open source

2) I need to have it integrate into a large existing membership database easily

3) Handle multiple forums and high volume

4) Manage the database well

Let me know what you use and why! I would really appreciate your input.

Thanks

Anon

I'd suggest phpbb at phpbb.com

Lionhead uses it for their message boards. It looks nice and seems to have all the features that the UBB has. phorum isn't bad (you're using it right now) but I find it lacking in many areas.