I came across this term "gRPC " when talking to a CTO from UK. I heard of RPC but not "gRPC", so i did a quick search on Google and found out that it works similarly to Microsoft WCF, just that it supports different programming languages ranging from C++, C#, Ruby, Python, etc and it's developed by Google. WCF supports only .NET languages. To find out more here's a link https://stackoverflow.com/questions/35694273/whats-the-difference-between-grpc-and-wcf
One more thing that i would like to mention about WCF is, there's a community in the.NET Foundation that has started the effort to create an open source WCF (Currently WCF Client in development, but not the WCF core itself) targeting for .NET Core programming model. However it's still at a very infant stage and probably not ready for production use out of the box, unless user development team is willing to take on the extra effort to customize the codes and fix any new issues discovered.
The link to the WCF .NET Foundation https://www.dotnetfoundation.org/blog/2015/05/20/wcf-is-open-source
In ASP.NET Core, Visual Studio uses the Protobuf compiler to compile the proto code into C# code.
gRPC Web UI - https://github.com/uw-labs/bloomrpc which ease the testing for the gRPC service contract.
