The Accord.NET framework has been archived (discontinued) according to its founder. However, the global community continues to use it with decent activity on Stackflow. The codebase is mature and well-established and very well commented. There is only 1 active developer and development activity is decreasing year over year.

Project Background

• Framework: Accord.NET
• Author: Cesar Roberto de Souza
• Initial Release: May 2010
• Type: Scientific computing framework in .NET
• License: LGPLv3 and partly GPLv3
• Contains: Set of libraries, executable installers, and a NuGet package manager
• Language: C#
• Github: accord-net/framework
• Runs On: Microsoft Windows, Xamarian, Unity3D, Windows Store applications, Linux, and mobile
• Github Discussions: None
• Twitter: None
• Stackflow: None
• Samples: 25 samples available for download

Applications 

• Classification
• Regression
• Clustering
• Distributions
• Hypothesis tests
• Kernal Methods
• Imaging
• Audio and signal
• Vision
• Statistics
• Numerical linear algebra
• Numerical optimization
• Artificial neural networks
• Graph plotting and visualization
• Computer audition
• Signal processing