xunit.extensibility.execution by: James Newkirk, Brad Wilson

Includes xunit.execution.*.dll for extensibility purposes. Supports .NET 4.5.2 or later, and .NET Standard 1.1.

xunit.runner.visualstudio by: James Newkirk, Brad Wilson

Visual Studio 2012+ Test Explorer runner for the xUnit.net framework. Capable of running xUnit.net v1.9.2 and v2.0+ tests. Supports .NET 2.0 or later, .NET Core 1.0 or later, and Universal Windows 10.0 or later.

Xunit.StaFact by: Andrew Arnott

Make your xunit tests more closely emulate your application by running them on STA threads, with support for various SynchronizationContexts.