kyann 

Cross-platform FreeType bindings for C#.

OpenCVSharp package

nBayes (based on Paul Graham's spam filter) makes it easy to introduce statistics based decision making into your application. Whether it's spam filtering, or something else like artificial intelligence... More information

A C# implementation of html5 canvas API. Works on .Net and Mono using Cairo.

Simple C# library to detect percentage of skin in image. It use opencv and OpenCVSharp to do this (CvAdaptiveSkinDetector).