Has any one tried to build a CMS upto the size and complexity of Joomla or EE on CI?

[eluser]nmweb[/eluser]
It's possible but I would do some serious hacking to CI. Better support for modularity for example but also a more integrated support for multi-lingual content. I'm curious to see how EE2 is build upon CI and where they felt there were shortcomings in CI. I think Rick Ellis said somewhere EE2 was built on an almost stock version of CI and I'd like to see his approach.