time environment (virtual machine component) of .NET framework Common Intermediate Language (CIL), an intermediate language that can be executed using an implementation of CLI Common Language Runtime, the virtual machine component of Microsoft's implementation of the .NET Framework. .NET standard libraries Base Class Library (BCL) Mono, an open source implementation of .NET Framework, used in many places including Unity and Xamarin. .NET Core, the open source cross-platform successor to .NET Framework. References Common Language Infrastructure CLI