Where you go for

AForge.NET

Open source C# framework for computer vision and AI.

Apache SystemML

Scalable, flexible machine learning for big data environments

DiffSharp

Automatic differentiation and tensor library for machine learning on .NET.

mlpack

Fast, header-only C++ machine learning library.

Patern Recognition and Machine Learning Toolbox

Open-source toolbox for pattern recognition and machine learning algorithms.

DecisionTree.jl

Interpretable decision tree and random forest models for Julia.