GUI for building connected blocks

[citromatik]

Hi all

Maybe a long shot...

I am trying to figure out how to build a GUI for creating and managing pipelines graphically, i.e. objects (blocks) connected by different relationships (lines). In other words, I would like to graphically create plots like this one: http://www.ebi.ac.uk/~mp/graph.png but be able to reorganize (drag them), reconnect, create new blocks, connections, etc.

Is anyone aware of any framework (or whatever) that would allow to do something similar?

How would you face the problem?

Thank you very much in advance,

M;