It could be also possible to write the server in Java,
and directly communicate with the GSTNet plugin via TCP.
For this I would just need to know the network protocols and datastructures used
by GSTNet.
Expanding this to use in Java should not be the problem from the technical side,
although it needs some indepht buildup to have a fluent communication.

3dgs is fine for using it as the displaying client. but as basis for the Server solution it sucks.