Unfortunately, there have been quite a few automated spam posts from anonymous posters in the today, and so I've had to disable anonymous posts in this forum (Open Discussion) to stop them.
At this stage there haven't been any spam posts in the other forums (Help, Compiler Problems, etc), so anonymous posts are still enabled there. If the spammers move there, it will have to be disabled there too. It's possible that not being able to post here will deter the spammers, so I'll try turning anonymous posts back on in a couple of weeks and see if they've gone.
In the mean time, anyone who wants to post here but doesn't have a SourceForge.net account has two options - you can sign up for a SourceForge.net account, or you can log in using an OpenID provider recognised by SourceForge (ie, if you have a Google account, you can use that).