Ella is opensource CMS based on Django framework, designed for flexibility.
It is composed from several modules:
Currently, we released the 3.x version which features a major cleanup of the code a removal of unneeded dependencies.
More news are on the way as we are going to make a nicely-tailored admin specifically made for the need of news writers and editors.
Docs are hosted on readthedocs.org, go to http://ella.rtfd.org.
Have a look at the docs: http://readthedocs.org/docs/ella/en/latest/quickstart.html.