Hi folks,
In last couple of months I’ve been developing Open Source GLSL demo development environment based on Eclipse IDE, called: Synthclipse.
Its main purpose is to help making GLSL demos but it’s kind of Java gaming related since it is written in Java and can be used as ordinary GLSL editor (for your games, of course 
).
I’ve finally released version 0.1.0 of the Synthclipse.
Here’s the web site: synthclipse.sourceforge.net
And here’s a screenshot:
More screenshots you can find here.