If you are unsure which CMS would be right for you for a certain project then openCMS could help you out.  Basically it is a site that runs all forms of CMS systems, from blogging platforms and image galleries to full CMS systems.  This way you can try multiple systems, both frontend and backend functions without having to download them all, making it easier to see which CMS will fit the job that you need it for


http://www.opensourcecms.com/



EDIT: oops I meant to post this in C.M.S links not in this one...sorry