Sitecake - Drag and drop CMS for HTML websites. It's flat file CMS so it's pretty fast.
Inkbunny - Helping furry artists and story-tellers share their work.
Anchor CMS - Free and lightweight blogging system
Weasyl - Open-source social art gallery
Textpattern - Textpattern is an elegant content management system that is free, open source software.
Hamail Art Gallery - Hamail Art Gallery is one of the leading art galleries providing an online platform to the creators and skillful people to show their stuff.