How is CEGUI licensed?
Up and until version 0.4.1, CEGUI is licensed under LGPL, which basically means you can dynamically link to it (ie. use it as a library) in a non-GPL project, as long as you fulfill the other requirements of the LGPL. However, from 0.5 on the library is released under the MIT license, which is less restrictive then LGPL. You may for example statically link to libraries. The main reason for this switch is the fact that the Ogre3D project has started to provide dual licensing to allow console development. And in order to keep CEGUI as their preferred GUI system, we have switched as well.