If you are implementing your own Moonlight game streaming client that can use a C library, you probably want the code here.
Moonlight-common-c requires the specific version of ENet that is bundled as a submodule. This version has changes required for IPv6 compatibility and retransmission reliability, among other things. These are breaking API/ABI changes which make Moonlight-common-c incompatible with other versions of the ENet library. Attempting to runtime link to another libenet library will cause your client to crash when connecting to recent versions of GeForce Experience.