Are there any GUI libraries that work well with LWJGL 3 and have decent documentation. I tried using NanoVG but there is very little documentation.

See:

- https://github.com/orange451/LWJGUI
- https://github.com/SpinyOwl/legui
- https://github.com/SkyAphid/Clear/
- https://github.com/kotlin-graphics/imgui
- https://github.com/LWJGLX/lwjgl3-swt

Other than NanoVG, LWJGL has bindings to the Nuklear & Yoga libraries, which might also help with GUI development.

How do I actually turn these into libraries. I'm not familiar with maven or gradel, and have no idea on how I actually use these as libraries.

how can i use https://github.com/kotlin-graphics/imgui whit java?

Obtain a binary release of imgui, either via the direct downloads on https://github.com/kotlin-graphics/imgui/releases or via Maven/Gradle ( see https://github.com/kotlin-graphics/imgui#how-to-get-it ). Those are jar files containing JVM .class files in the end and can be used with any JVM language, such as Java. You just have to use an IDE with the binary jar files added to the build/classpath and explore the API.