Help:LanguageTool

LanguageTool is a system for style and grammar checking in a number of different languages, that can be incorporated in VisualEditor through use of an external web service. The text is checked against rules, and if violations are found then warnings are shown in the editor. It will not itself change the text, it will only act as an advanced spell-checker.

LanguageTool has rules for about 20 languages, and new languages are added continuously. Quality and completeness may vary, but it is easy to extend the system with new rules. There are both an upstream rule editor and a local one. The upstream editor should be used for stable general rules, while the local one should be used during testing and for project specific rules.