The OWASP ZAP core project
Now continued as OculiX — see oculix.org
Programmer-friendly testing framework for Java and the JVM
SoapUI is a free and open source cross-platform functional testing
Flexible, lightweight multi-language test reporting tool
API automation and load testing framework
SoloPi Automated Testing Tool
Coverage-guided, in-process fuzzing for the JVM
The Open Source Test Automation Platform
Test automation made simple
Android unit testing framework
Most popular Mocking framework for unit tests written in Java
Gateway service providing dynamic routing, monitoring and more
State of the art mutation testing system for the JVM
Java GUI-Less browser, supporting JavaScript, to run against web pages
Database Subsetter and Relational Data Browser
Editor for Fixed Width, Csv and Existing Xml files.
Automated tests with databases: prep, verify, restore tables
Enterprise integration testing framework
Simple example of draw and rotate 3D box
A Java Utility Class To Create Combinations of Existing Arrays.
The Interactive Exernal Accessor Tool for develop, test and support.
A web application for testing webservices