Very well done, but not the first: 2 years ago Jetpac released DeepBeliefSDK (https://github.com/jetpacapp/DeepBeliefSDK). They were acquired by Google and development stopped. But the demo has been ported (http://waylonflinn.github.io/DeepBeliefSDK/) using a newer toolkit called webblas (https://github.com/waylonflinn/weblas). Reddit discussion about webblas at (https://www.reddit.com/r/MachineLearning/comments/41luif/gpu...) which has some more links and thoughts about this kind of thing. One more toolkit, written during a hackathon and still getting started, is gpu.js (https://github.com/gpujs/gpu.js/).