- Brain.js A neural network library
- svmjs SVM library
- Numeric.js Performs sophisticated numerical computations.
- Node-sylvester Linear algebra library
Most of these use node.js for training on the server-side. They generate a classifier(usually in JSON) which can be used to make predictions on the server-side. Often the classifier generated is too heavy to be useful, but there are several non-trivial uses as well. Hopefully I shall be coming up with a neat application soon 😉