What does the "F" stand for? Fabric? (Neo)Forge? Fun? Who knows...

It's a small, jij-able library that allows creation of server side guis.

• This project is a fork of sgui, adapted to work with both Fabric and NeoForge alongside continuous support for multiple Minecraft versions.

Add it to your dependencies like this:

dependencies {
    modImplementation(include("de.clickism:fgui-fabric:1.0+1.21.11"))
}

dependencies {
    jarJar(implementation("de.clickism:fgui-neoforge:1.0+1.21.11"))
}

After that you are ready to go! You can use SimpleGUI and other classes directly for simple ones or extend them for more complex guis.