StepTalk is the official GNUstep scripting framework. It is more than a scripting framework with an illusion of single objective environment between objects of scriptable servers or applications. It is language independent, but the default scripting language is Smalltalk.
Java GUI Builder lets you decouple your GUI building code from the rest of your application. Using an XML description, it will build appropriate windows, controls, and objects for later retrieval by the mainstream code.