GraalVM allows you to call one programming language into another and exchange data between them.

To enable interoperability, GraalVM provides the --polyglot flag.

GraalVM allows users to write polyglot applications that seamlessly pass values from one language to another.

Truffle is a Java library for building programming languages implementations as interpreters for self-modifying Abstract Syntax Trees. When writing a language interpreter with Truffle, it will automatically use the GraalVM compiler as a just-in-time compiler for the language.