LanguageTool is a style and grammar checker that currently supports English, Polish, German, French, Dutch, and other languages to a different degree. It scans the words and their part-of-speech tags for occurrences of error patterns, which are defined in an XML file. More powerful error rules can be written in Java.

Changes:
Many error detection rules have been updated, especially for French, Catalan, German, Portuguese, Russian, Esperanto, and Breton. Several small bugs have been fixed.

URL:
LanguageTool – Freecode

LanguageTool 2.2-0811_languagetool_2.2.png