Graham's excellent Dialog Designer now has an online forum. You can join here.
If you are not familiar with Dialog Designer, you should try it out. It is a very slick tool that lets you build GUIs in Magik with a drag-and-drop interface. All the difficult GUI generation code is stubbed out for you and you can focus on building the engine/database behavior.
You can read sworldwatch blog posts about Dialog Designer here.
And it is open-sourced by iFactor Consulting so you have free access to the product! You can read more on the product page here.