I intend to continue squirriling, bit by bit, as time goes by. But there's definitely enough there already for the absolute basics. After installing the three NBMs in the ZIP file referred to above, you'll have a file template:
When you finish the wizard above, you'll be able to run scripts (right-click in the editor and choose Run Groovy Script), with the results typically in the Output window:
By the way, using the technique shown a few days ago, you can continue stepping through Groovy to your heart's content:
If you don't like the fonts and colors I chose for you, go to the Options window, to the Fonts & Colors tab, to change them:
Use these three NBM files at your own risk. Possibly it will destroy everything you've ever believed in. Or maybe just your IDE, which is probably worse. So be careful. It has not been tested, I created it on a post-6.0 Beta 2 build on Ubuntu, so possibly you won't even be able to install it. I would be interested to know what people think of it.