The boards software here is Vbulletin 3.0. and it does a bit more than just the forums, (I'm not clued into the details, but suffice to the say the board software is linked into ngemu to the point that if we switched it would most likely mean require a redesign for the site).
Regarding guests. They can read/download etc... I think about the only thing they can't do is post in the forums themselves.
BTW Double posting is frowed upon here. If you must add something, use the edit option in future.
__________________
Superior marketing of an inferior product will always win over inferior marketing of a superior product.