Fast Interactive force-directed graph layout engine

I need a fram开发者_运维百科ework/library which will enable me to develop a realtime interactive graph simulation. The user must be able to dynamically add nodes and edges. I have found Prefuse and its force directed layout and I really like it. But it is not fully thread-safe, and doesn't perform all that well -- maybe it has problems with big graphs?

Are there some decent alternatives? I know about Flare, but I have no desire to learn ActionScript and would rather stick with c++/java/c#.

yFiles is a good commercial library (Java, C#, ActionScript, Javascript versions available) for interactive graph visualization, that supports wide range of layouts, and has no problems showing very big graphs. You can test its capabilities quickly by trying yEd, which is based on yFiles.

The question is a bit old but still let me introduce another commercial option for C#. GraphX for .NET PRO is capable of rendering thousands of vertices and edges simultaneously and supports variety of force-directed layouts. There is also free open-source version which is less performant but supports easy styling features.