I'd like to see a static site generator that still runs some kind of administrative backend somewhere. Then I could have clients or friends I do sites for log

I'd like to see a static site generator that still runs some kind of administrative backend somewhere. Then I could have clients or friends I do sites for log in to one of my personal machines and enter new stories/content, and it would generate the pages and push the updates. That would combine the best of a simple CMS with the best of static generation. Does something like this already exist?