Jesse van den Kieboom
Creating ruby bindings for your GObject application or library is still a lot of work, although the macro's and functions provided by ruby-gnome2 make it a pretty easy task (usually function implementations are one liners). This also makes it a good candidate for automatic generation of bindings!
As I was working/thinking of providing ruby bindings for gedit, I discovered that all ruby bindings currently are crafted by hand (much unlike the GObject python bindings). I therefore set out to provide such a tool to generate bindings for you, RbgTool. It is able to abstract the to-be-bound classes and types into a XML definition, and generate bindings from that definition automatically. I've only tested it on gtksourceview2 (for which I didn't write hardly any custom code in the bindings).
The project page, and source code can be found at http://trac.novowork.com/rbgtool.