What algorithms are good for interactive/realtime graph-drawing?

Question

What algorithms are good for interactive/realtime graph-drawing for live data and direct-manipulation?

Failing that - what libraries do you use to draw graphs?

Answer 1

the prefuse visualization toolkit looks like a good candidate.

Prefuse supports a rich set of features for data modeling, visualization, and interaction. It provides optimized data structures for tables, graphs, and trees, a host of layout and visual encoding techniques, and support for animation, dynamic queries, integrated search, and database connectivity. Prefuse is written in Java, using the Java 2D graphics library, and is easily integrated into Java Swing applications or web applets. Prefuse is licensed under the terms of a BSD license, and can be freely used for both commercial and non-commercial purposes. (from the homepage)