canvg is a SVG parser and renderer. It takes a URL to a SVG file or the text of an SVG file, parses it in JavaScript, and renders the result on a Canvas element. The rendering speed of the examples is about as fast as native SVG.
Waterbear is a toolkit for creating drag-and-drop programming languages, with some example languages you can play around with and learn from. The goal is to make it easy to wrap other existing languages with Waterbear blocks to create draggable, snappable syntaxes for them.
D. Johnson, and T. Jankun-Kelly. Proceedings of graphics interface 2008, page 163--168. Toronto, Ont., Canada, Canada, Canadian Information Processing Society, (2008)