We need to start with the Raphael library, providing cross browser abstract layers for rendering vector objects.
The following bulleted features are stolen directly from their home page:
- connecting vector objects with various types of arrows
- interacting with connections and objects
- custom handlers for various events
- bent lines smoothing
- ready-to-use elements of well-known diagrams (ERD, Org chart, FSA, UML, PN, DEVS, LDM)
- hierarchical diagrams
- serialization (to/from JSON format, SVG export only in browsers that support it)
While Dojo does far more than vector graphics, it is well known for charting and graphing and it’s sharp looking gauge package in particular.
Paper.js has its own set of impressive demos and seems much more approachable than Processing.js. This is a nice tool, powerful, not too complicated.
CAKE is a scene graph library that includes tweeing. This is the most Flash-like library in capabilites: the Missile Fleet demo runs at nearly 300fps on my PC. The documentation is a bit thin but it exists and there is only one tutorial. This is a go-to for fast, flashy graphics.