What have you done so far in terms of learning machine learning? There's quite a few resources for getting a good foundation, if that's something you might need.

Ironically, looking dennybritz's comment, JS is particularly ill-suited for this, as, as far as I'm aware, there are no libraries for working on the GPU, which is tremendously useful for working with machine learning algorithms which usually are crunching lots of data.

However, I don't know much about karpathy's specific implementation and experiments, so there might be a reason he choose JS. I'm thinking its more likely to make visualizations easier rather than any computational reason though, so you might be stuck in a niche there.

You're right that JS is pretty ill-suited for implementing production-level Deep Learning architectures that operate on a lot of data, I think it's still well suited for explaining the concepts in a clear way. A lot of the models have intuitive (and visual) interpretations, something that can be nicely visualized with JS.

As for Karpathy's implementation, you're right, he chose JS for that reason. His library is meant as a tool for experimenting and teaching, not to deploy these models in production.

Op: Send me an email if you're interested in this (email in profile). I actually started something similar just recently at http://www.wildml.com/.

Nice blog! Yes I am interested in Deep learning, although am just a newbie. Right now I just read around in several blogs to get the idea. As for JS visualizations, TonicDev[1] is a nice option if someone wants a IPython style notebook in JS

[1] https://tonicdev.com

yep I am learning machine learning from Andrew Ng's coursera offering, which is quite good and hence sparked my interest in this field. also, i read few interesting blogs related to neural nets and machine learning to gain further info