Crow is a modern GUI builder for the GTK+ toolkit. It is an advanced
IDE-embeddable RAD tool designed to fulfill the needs of desktop programmers
who want to create multi-platform GTK+ based applications with minimal
GUI coding. Crow is full-featured yet lightweight: its tree-based Property
Explorer solves many GUI constructing tasks in a versatile manner without
additional popup dialogs. The project is targeted to develop a tool that
is coherent and productive for experienced GTK+ users as well as simple
and accessible for newcomers.

WWW: http://crow-designer.sourceforge.net/