http://old.zenhax.com or http://forum.aluigi.org
It's just html so no register, search, login or feeds
The forum is closed from 2011 and now acts only as historic archive, but in the 4 years (since 2007) that I kept it open it collected tons of information and helped lot of people.
Even if the latest post is dated 2011, there is still valuable content there like the research on Gamespy and many information about game security vulnerabilities.
My plan for Zenhax is having something completely community-driven and not mainly related to my stuff (I no longer have the free time I had in 2007), that's why I preferred to not reopen that forum.