Diff, Match and Patch Library http://code.google.com/p/google-diff-match-patch/ Neil Fraser

This library is currently available in seven different ports, all using the same API. Every version includes a full set of unit tests.

C++:

• Ported by Mike Slemmer.
• Currently requires the Qt library.

C#:

• Ported by Matthaeus G. Chajdas.

Dart:

• The Dart language is still growing and evolving, so this port is only as stable as the underlying language.

Java:

• Included is both the source and a Maven package.

JavaScript:

• diff_match_patch_uncompressed.js is the human-readable version. Users of node.js should 'require' this uncompressed version since the compressed version is not guaranteed to work outside of a web browser.
• diff_match_patch.js has been compressed using Google's internal JavaScript compressor. Non-Google hackers who wish to recompress the source can use: http://dean.edwards.name/packer/

Lua:

• Ported by Duncan Cross.
• Does not support line-mode speedup.

Objective C:

• Ported by Jan Weiss.
• Includes speed test (this is a separate bundle for other languages).

Python:

• Two versions, one for Python 2.x, the other for Python 3.x.
• Runs 10x faster under PyPy than CPython.

Demos:

• Separate demos for Diff, Match and Patch in JavaScript.

This library implements Myer's diff algorithm which is generally considered to be the best general-purpose diff. A layer of pre-diff speedups and post-diff cleanups surround the diff algorithm, improving both performance and output quality.

This library also implements a Bitap matching algorithm at the heart of a flexible matching and patching strategy.

http://neil.fraser.name/software/diff_match_patch/bitap.ps

[pre-diff speedups and post-diff cleanups] https://neil.fraser.name/writing/diff/ matching and patching strategy[http://neil.fraser.name/writing/patch/]