Grpc.Core is the legacy C-core-based gRPC library for .NET; the request names it, and the current official route is the gRPC framework itself 1, which offers a universal RPC framework using Protocol Buffers for defining services. Its official doors are not shown in the sources, so the answer below is limited to what the gRPC source states; the sources do not confirm a separate Grpc.Core package page.

1. 1

   gRPCgrpc.ioverified and signed

   High-performance open source RPC framework that connects services using Protocol Buffers for service definitions, with pluggable load balancing, tracing, health checking and authentication 1.

   WebsiteDocs

   +16 community tools built for it

   for agents: gRPC · RPC · gRPC

2. 2

   ghzghz.shwebsite read, tools not yet checked

   gRPC benchmarking and load testing tool that tests unary and streaming calls from proto files, protoset bundles or server reflection 9.

   WebsiteDocs

3. 3

   MsgPack Namespacemsgpack.orgverified and signed

   MessagePack serialization primitives for CLI, covering packing and unpacking of binary-serialized objects 8.

   WebsiteDocsGet started

   for agents: msgpack · messagepack · serialization