What is CI's relation to Ellislab?

[eluser]J3roen[/eluser]
I've been checking out CI for a few days, and I like very much. :-)

The modular approach (even within MVC) is very cool. Very easy
to extend/replace CI classes with your own.

One thing that bothers me is, how is EllisLab involved with CI? Is
it owned? And if so, will it allow redistribution even on commercial
projects?. And why doesn't the CI site itself use CI, but instead the
expressionengine.

Other thing is, it's been 6 months since the last release. Is it still
actively being developed?