Many (but not all) use GML as a data format.
- good to have SVG view?
Mind Mapping is a subset.
Piddle is is a Python module for creating two-dimensional graphics in a manner that is both cross-platform and cross-media; that is, it can support screen graphics (e.g. Quick Draw, Windows, Tk) as well as file output (PostScript, PDF, GIF, etc.).
Mathematica and its clones
- looks like a Flash app, but does have export of JPEG/PNG/SVG
- hey, it actually does connecting vectors that move with either end! (Unfortunately they're right-angled, not pretty curves.)
TouchGraph: for rendering, not editing
- what does The Brain use for WebApp? It's not Flash (in Feb'2013)
- http://raphaeljs.com/ SVG
- ProtoVis http://mbostock.github.com/protovis/
- CoffeePhysics http://badassjs.com/post/18503583619/coffeephysics-a-fast-new-physics-engine-written-in
- http://bl.ocks.org/rkirsling/5001347 editor
- Software Galaxies code-dependencies viewer https://github.com/anvaka/pm/tree/master/about#software-galaxies-documentation
See also manual diagram tools.