PRIMA homepage
Computers, Open Source, Software, GUI - Prima. Toolkit for multi-platform GUI development.
http://www.prima.eu.org/
GUI
Open source GUI for less powerful or old computers.
Computers, Open Source, Software, GUI - KronoJunior. Open source GUI for less powerful or old computers.
https://kronojunior.sourceforge.net/
Java Gui Builder Project Home
Computers, Open Source, Software, GUI - Java Gui Builder. An engine that reads XML files describing graphical user interfaces layout.
https://jgb.sourceforge.net/