An Open Source language checker for English, French, German, Polish, Dutch, Romanian, and other languages. This is a rule-based language checker that will find errors for which a rule is defined in its XML configuration files. Rules for more complicated errors can be written in Java. You can think of LanguageTool as a tool to detect errors that a simple spell checker cannot detect, e.g. mixing up there/their, no/now etc. It can also detect some grammar mistakes. It does not include spell checking.

Launched as an independent initiative, the project is led by a group of recognized project leaders. Code is developed on a volunteer basis. The software and all associated features are available under a single free/open-source license (weak copyleft). The copyright is owned by an individual. The project works on the basis of informal anarchic goal-setting. Decision making is decentralized.

The software is predominantly developed by several people collaborating in an informal or not industrialized way.

Current development status is stable.