This is just a quick little implementation of Delaunay Triangulation in JavaScript. It was mostly ported from Paul Bourke's C implementation, but I referenced some bits from another JavaScript implementation and rewrote a bunch of things in ways more amenable to fast JavaScript execution.
Essentially, you pass Delaunay.triangulate a list of vertices (which should be a bunch of two-element arrays, representing 2D Euclidean points), and it will return you a giant array, arranged in triplets, representing triangles by indices into the passed array. (This representation is a little bizarre, but object allocation is too slow for this library's original use case. Yes, really.)
Notably, it runs in subquadratic time, making it the fastest JavaScript implementation of which I'm aware. (Okay, it doesn't really, but it'd be trivial to modify to run in subquadratic time, I just havn't done so yet.)
To the extend possible by law, I have waived all copyright and related or neighboring rights to this library.