LanguageTool - Style and Grammar Checker for 25+ Languages

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. Receive tips on how to improve your text (including punctuation advice etc.) while typing an e-mail, a blog post or just a simple tweet. Whatever language you're using, LanguageTool will automatically detect it and provide suggestions.