<p>I have a data structure that represents a directed graph, and I want to render that dynamically on an HTML page.  These graphs will usually be just a few nodes, maybe ten at the very upper end, so my guess is that performance isn't going to be a big deal. Ideally, I'd like to be able to hook it in with jQuery so that users can tweak the layout manually by dragging the nodes around.</p>

<p>Note: I'm not looking for a charting library.</p>

JsVIS
was pretty nice, but slow with larger graphs, and has been abandoned since 2007.
prefuse
is a set of software tools for creating rich interactive data visualizations in Java.
flare
is an ActionScript library for creating visualizations that run in the Adobe Flash Player, abandoned since 2012.