SigmaNil is an open-source software library developed by Machinetutors.

It is a framework for natural user interfaces with elaborate features, such as finger level precision hand shape recognition, hand gesture recognition, and hand skeleton tracking. SigmaNIL framework also provides customization tools for each of these advanced features.

The framework is designed to support all depth sensor devices and base libraries such as OpenNI and KinectSDK. It is also designed so that developers can enhance it by adding new powerful modules.