The beta application allows you to sign in with a Flood account, Google+, or Facebook. You can add nodes that perform arithmetical operations, shapes, and even functions.
It's built with Grunt and Bower, and uses libraries like three.js and Bootstrap.
Peter's other project is verb (GitHub: pboyer / verb, License: MIT), a library for creating and manipulating NURBS surfaces. It works with browsers and Node and supports advanced tools like derivative evaluation, adaptive tessellation, and intersection.
The examples include things like arcs, Béziers curves, and various extrusions. You can rotate the examples if you click and drag.
NURBS are used in CAD, I don't think they're particularly popular for game graphics, so presumably Peter intends to use this with the Flood project.