GraalVM is a high-performance embeddable runtime for applications written in JavaScript, Python, Ruby, R, WebAssembly, JVM-based languages like Java, Scala, Kotlin, and LLVM-based languages such as C and C++.
LLVM Toolchain is a set of tools and APIs for compiling native projects, such as C and C++, to bitcode that can be executed with the GraalVM LLVM runtime. It is aimed to simplify ahead-of-time compilation for users and language implementers who want to use the GraalVM LLVM runtime.