Welcome to the new forum!
For various reasons, the forum was converted to use Discourse, instead of SMF. There are some functionality that did not make the move, sorry about that, but for the most part, all the posts should be there. Categories are roughly the same too.
To simplify the conversion process, password data was not moved over. You will need to reset your password, and create a new one to login. New user accounts are disabled for now.
Avatars were moved over, but there were some conversion issues, so please update your avatar again if there is a problem.
For now, the old SMF forum is still available, but set to Maintenance mode. This is to ensure that no new posts are added after the move. If all goes well, it will be removed at some point in the future.
If you have any further issues, please shout.