Open Source Java Diff Tools

Eclipse comes with an internal diff / compare editor, but if you prefer a third-party one, this plugin opens an external merge or diff tool for you. After you open two versions of a file in the internal eclipse compare editor, this plugin either opens an external diff tool automatically or you can choose that this plugin opens the external diff tool after you press a button in the toolbar of the internal compare editor. Furthermore the plugin can (optional) format java code before the compare. This simplifies the compare if the code of 2 versions of a file is different formatted.

External diff Tool is an Eclipse plugin that allows the launch of an external diff tool for file compares rather than the default built-in Eclipse diff tool. This plugin doesn't replace the built-in Eclipse tool. It only adds a new menu item to the GUI.

Platform-independent PostgreSQL diff tool that is useful for schema upgrades. The tool compares two schema dump files and creates output file that can be used for upgrade of old schema. Project sources and issue tracker has been moved to https://github.com/fordfrog/apgdiff.

xmldiif is a library which allows to show diff between xml documents

Provides tools, supporting quality management or quality assurance for software: Assessment execution (ISO 15504 (SPiCE), AutomotiveSPiCE, CMMi), diff tool calculating sizes (SLoC) of diffs, identification of conditional compilation, and more.

JMeld is a visual diff and merge tool. It is build to be fast with large files and runs on any operating system. Development on sourceforge has stopped. The project continues at github. https://github.com/MrKuip/JMeld

A cross-platform file diff and directory diff Tool. Also contains an SCM project which uses the stand-alone tool. Go to https://vmaster.sourceforge.net to see screenshots or to start the diff tool.

XinDiff is a diff utility implementing WinDiff like GUI by an improved LCS algorithm. The key feature in addition to WinDiff is in-place comments for code review.