Java graph library for dynamic visualisation

Take a look at GraphStream, as shown from their demo video you can do some fancy stuff with graphs using their library.

Take a look:

• GEF - GUI components for graphical editing, including graphs, (Eclipse) SWT based
• JGraphX - former JGraph, not actively developed since March 2020
• Piccolo2D - (Eclipse) SWT based
• JUNG - last released in 2010 (as of 2020); was very popular back then
• yWorks - not open source, not free
• JGraphT - data handling and algorithms only, no integrated visualizaiton, though supports JGraphX visualization

Prefuse is pretty and powerful. The website is no longer there so here is an archived version