JUnit and NUnit are open source unit testing frameworks; the former for Java applications, the latter for .Net programs.

Diffblue makes a free version of its AI-powered Java unit testing solution available for developers on open source software projects.

In the Preface for Effective Unit Testing: A Guide for Java Developers , author Lasse Koskela states that although the impetus for Effective Unit Testing was to "write a Java edition of Roy ...

A UK-based startup founded by University of Oxford researchers launches an AI-powered Java unit testing solution, including a free-for-Java-devs Community Edition.