List of CLR VM implementations:
* CoreCLR, part of .NET Core
* Mono, which was acquired by Microsoft a few years ago | Source
There used to be more (below), but interest appears to have waned after an early surge.
Shared Source CLI (aka "Rotor"); SSCLI Essentials is a good place to start to understand the CLR codebase ("runtime") itself.
CLR Heap Encryption proof of concept
Last modified 14 January 2024