openSCADA® is an open source SCADA system written in JAVA
Bunch of Apache Maven plug-ins and tools
a recent files api for java
a sliding info component for java.
A tool which is used to customize jre and your java application
An Eclipse plugin for running JPA queries
Effective Unit Testing for Java EE
Open source Extract Transform Load engine written in Java
Eclipse Plugin to validate Hibernate ORM files against @Entity files.
Robotypo Web app hosts battles between robots - simple Java programs.