The old method was too inflexible (depending on consecutive events to batch) that it couldn't really handle stressful cases like high polling rate mice combined with multiple gamepads reporting motion sensor events.
Moonlight Streaming Core Library
Moonlight-common-c contains the core GameStream client code shared between Moonlight clients, including Moonlight PC, Moonlight Android, Moonlight iOS, and Moonlight Chrome.
If you are implementing your own Moonlight game streaming client that can use a C library, you probably want the code here.
Note to Developers
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.