Cool! This is exactly the type of plugin that is why the GDE/jMP exists!
Sounds good 
Tell me if you need any info on jMP or the SceneExplorer. Nothing is final yet and we can build in specific requirements for your plugin. I hope you are using the existing SceneViewer to display stuff? Plugins are not supposed to open up a render window each, it would end up in a mess of oGL windows and lots of problems/overhead.
Cheers,
Normen
At the moment i programm it as standalone
As soon i finished i will make it GDE compatible. And yes i'm only using ine GL window 
Is it even possible to open two GL windows? If yes, it doesn't work for me 