GraalVM is an ecosystem and runtime that provides performance advantages to JVM languages like Java, Scala, Groovy, and Kotlin as well as other languages. It includes a just-in-time compiler called Graal that improves efficiency, polyglot APIs for combining languages, and SDK for embedding languages and creating native images. Installation can be done with the JDK which includes Graal starting with JDK 9, or by directly downloading GraalVM from Oracle's website.