Design patterns implemented in Java

Android Unit Testing Framework

Java (and original) version of Hamcrest

Java/Swing GUI testing made simple!

jblockchain: Einfache Blockchain-Implementierung für Demonstrationszwecke

[sourceforge] A somehow old self-written Java library with UI stuff (swing components and a micro-architecture), AOP stuff and a maven-buildmac-plugin

[sourceforge] A nice little movie manager app written in Java/Swing with some very filthy UI features ;)