Did you ever have to work with multiple Java projects and each of them was on different version Java or any JVM tools?
SDKMAN is a CLI tool for managing multiple versions of Java and JVM tools. I started using this tool in its earlier form known as GVM(Groovy Environment Manager). I used it for managing multiple versions of Groovy and Grails. With GVM, I could easily switch Groovy/ Grails versions to the one required by my project I was working on a particular day. As the tool became SDKMAN, it added support for several tools in the JVM ecosystem, including JDK. Today I manage Java, Groovy, Grails, Micronaut, Gradle etc. with SDKMAN.
Ability to switch between versions of JDKs is more useful today than ever. You could not only switch between versions (like 8, 11) but also pick builds provided by different vendors such as AdoptOpenJDK, Amazon, Azul etc. You can even manage versions of GraalVM with SDKMAN.
If you are using SDKMAN, the command
sdk flush archives can be handy. It cleans up the downloaded archives. The first time I discovered this command, I managed to get 11GB of disc space!