Widget builders?

[Gorshkov <listsubscriptions oghma on ca>]

On a "In-no-way-related" note ..... I've come across GOB2 as a widget builder 
for gtk .... Because I'm going to have to be re-using major parts of my 
interface in indifferent programmes, I was wondering if anybody has had any 
experience with it - or, failing that, if they are aware of any other 
widget-building programmes that might help simplify the task?