This is only slightly related to SEO, but it was interesting enough to me to post about it. SEOs inevitably end up facing the task of deciding which system is best to use on their site - whether it is a blog, content management, forum, ecommerce or portal system. Although the following site does not evaluate these systems for search engine friendliness, it does offer the ability for you to actually try out all the popular open source systems (including the admin sections) before you ever bother to install them on your server. I was absolutely glued to this site last night, as I tested different systems. Here is how it works: The administrator username and password is given for every system and each system is deleted and re-installed every two hours. This allows you to to add and delete content, change the way things look, basically be the admin of any system here without fear of breaking anything. You have to play with this to really appreciate the value of it. Check it out at www.opensourcecms.com.