Osiris
Osiris is very-easy-to-use GUI (graphical user interface) system for OCaml. It's built on top of the OCaml Win32 native API binding and enable the creation and control of most of the standard user interface components.
GTK port
I'm looking for people interested in porting Osiris to LablGTK so it could work on any GTK supported platform. Contact me if you're interested.
Distribution
Full sources, some samples, in a zip here.
Osiris requires the OCaml Win32 API (CVS version)