[Koha] Koha and OpenBook

I've been helping with a small non-profit library. They've been needing a new library system and Koha came to my attention. I also heard about OpenBook recently and wanted to try it out as well, but it seems that the website for it has been down. Does anyone know where to find OpenBook and what is going on with their website? Also, what are the current differences feature-wise between Koha and OpenBook? Those are the two systems I've been looking at lately, but I'm open to any other suggestions that someone may have. The more choices we have, the better. Thank you for your help. Rob Campbell