GraalVM is made at Oracle Labs, which is the department of Oracle for research and development teams. GraalVM is a high performance polyglot virtual machine that supports many languages and is embeddable in native and java applications. GraalVM is high performance which means it runs your programs fast. It is polyglot meaning that it will support running programs in different languages and that you can mix these languages inside a single program. It is embeddable, so you can enhance your existing application, whether it is a Java application or a native application. The project is open source and is completely written in Java.
gRPC is a high-performance RPC framework created by Google. It uses Protocol Buffers to exchange data between services instead of JSON. Google is using it for almost all its internal communication. If Google is using gRPC, why is the biggest part of the software engineering world still using REST?