LanguageTool is an Open Source proofreading software for English, French, German, Polish, Russian, and more than 20 other languages. It finds many errors that a simple spell checker cannot detect.

LanguageTool is freely available under the LGPL 2.1 or later.

For more information, please see our homepage at https://languagetool.org, this README, and CHANGES.

For technical details, see our wiki.

The development overview describes how you can contribute error detection rules.