The editor is a general purpose editor framework which is plugin-based and uses Ogre and CEGUI. One of the primary plugins for the editor is a scene editor which lets you place and manipulate game objects based on the GOOF framework. The GOOF framework is another topic altogether, but is kinda like an engine for Ogre.

I'm pretty CEGUI through its paces and its holding up very well

A couple weeks ago I looked for alternate skins for CEGUI besides TaharezLook and WindowsLook and was surprised that there wasn't much available yet. There is a Marti skin, but it doesn't have ports for all the same controls that are available under WindowsLook (yet). I was mostly surprised because I figured after the "Falagard" functionality was done we'd see a ton of skins pop up

Anyhow, keep up the great work and thanks for CEGUI!
Clay