Thiis is another CMS.

http://nliautaud.fr/thiis

A strange one. Thiis is one file, without flat-files, database, installation or anything like that (thiis thing store everything directly in its own source code).

It's minimal and twisted but it can do many powerfull things with its fully editable hierarchical data system, like having unlimited user accounts, rights management and any other custom data. Its powerfull syntax may be used anywhere to build dynamic pages and templates. And everything is in a fancy admin interface with previewing and undoing. And there is file browsing. And internationalization. And url rewriting. And rss feeds. And many other things.

The development version include a lot of improvements, a much better admin interface with drag&drop etc. And bugs.

There is also a deeper fork in alpha state, targetting flat-files content and pluggeable features here : https://github.com/nliautaud/thiis-flat