Asia_Expat - 4:21 pm on Nov 23, 2009 (gmt 0)

My vote goes to the latest IPB version (version 3)... Out of the box, it's very well optimised from an SEO perspective. There's still a little tweaking to do but it has it's own FURL system, correct 301 header functionality, a basic robots.txt for you to build on... and crucially, there's a strong customer community of SEO experts on that software. With the latest version of the software, there really is no need for third party addons, and this is a major selling point IMO.

I'm lucky because I purchased my IPB license ages ago and can use the software forever. Nowadays, I believe it's a bi-annual fee. You do get rock solid security however, and this is crucial in forum software. They are also doing some interesting stuff with spam mitigation.