Hi. Something amazing just happened. vasilis margioulas left a cells-gtk package on my doorstep last night. LLGPL. It was written for Clisp and uses the CLisp ffi instead of UFFI, but I think an eager beaver could port it to UFFI pretty easily, making it available to other Lisps. As for OSes: win32 and linux have been tested. CLisp on Mac OS X does not have ffi yet. But if the project gets ported to uffi then it can run under other Lisps on Mac OS X and GTK for X. (GTk native for OS X is not there yet.)
Vasilis is a computer science teacher and was exploring declarative GUI programming (ala Cells) as contrasted with the Gui-builder approach. He has gotten cells-gtk to a very polished state, but will not have time for a while to extend it. I gather also his needs have been met. Anyway, he is putting the project up for adoption and I of course accepted.
But I think it needs its own project. GTk is quite popular it seems, and unlike LTk this interface does not run over a socket. I think also having it separate means you can list it under "Graphics" in your project directory, which may sound silly but I believe that directory will be exactly how people find stuff. This will also make it easier to find adoptive parents. :)
kenny