The Open Toolkit library is a fast, low-level C# wrapper for OpenGL, OpenAL & OpenCL. It also includes windowing, mouse, keyboard and joystick input and a robust and fast math library, giving you everything you need to write your own renderer or game engine. OpenTK can be used standalone or inside a GUI on Windows, Linux, Mac.
AutoFixture is an open source library for .NET designed to minimize the 'Arrange' phase of your unit tests in order to maximize maintainability. Its primary goal is to allow developers to focus on what is being tested rather than how to setup the test scenario, by making it easier to create object graphs containing test data.
Suave is a simple web development F# library providing a lightweight web server and a set of combinators to manipulate route flow and task composition.
Bolero brings Blazor to F# developers with an easy to use Model-View-Update architecture, HTML combinators, hot reloaded templates, type-safe endpoints, advanced routing and remoting capabilities, and more.