hanswolff 

Very fast .NET in-memory message queue that uses TCP/InProc transport

Curve25519 is an elliptic curve, developed by Dan Bernstein, for fast Diffie-Hellman key agreement.

Simple SMTP Server using .NET 4.5 async pattern

Lightweight offline classification of IP addresses (includes IP ranges of Amazon AWS, Azure, DigitalOcean, OVH)

Cloo is an open source, easy to use, managed library which enables .NET/Mono applications to take full advantage of the OpenCL framework.

ProtoBuf message serialization / deserialization for RedFoxMQ

Equinox is a state of the art email messaging library targeting the .NET Framework and the Mono Runtime. The library contains full implementations for the IMAP, SMTP and POP3 protocols. In addition the library... More information

FIDO Universal 2nd Factor (U2F) library for .NET. Please have a look at the project page for examples.