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.
XML-Grammar-Fiction is a Perl package that provides processors for lightweight markup languages and corresponding XML grammars for writing prose (e.g. stories, novels, and novellas) as well as screenplays. The XML grammars can in turn be translated to XHTML and DocBook/XML. XML-Grammar-Fiction currently offers only very basic functionality, but has good support for UTF-8 and allows one to write bidirectional texts conveniently. It is still under development and may exhibit some quirks.
After the Deadline checks English spelling, misused words, style, and grammar using artificial intelligence and natural language processing. This add-on adds After the Deadline's smart technology to the Firefox browser. Now you can check grammar in your online word processor, spell check your Web mail, and send tweets with confidence.
After the Deadline for OpenOffice.org is a smart English grammar, style, and contextual spelling checker for OpenOffice.org. The grammar checker highlights common errors in your writing. The style checker (off by default) finds passive voice, clichés, redundant phrases, and complex expressions. The contextual spelling checker looks for misused words and reports them to you. This extension communicates with an open source software service to check your writing. You may run your own server or use that provided by afterthedeadline.com. Text sent to afterthedeadline.com is sent over SSL and none of it is kept.
KeyBoards is a cross-operating system platform that synchronizes short text messages or URLs. It is designed to be used for composing messages on a desktop system with a real, comfortable keyboard, and then sending them to a mobile device for transmission as an SMS. It is ideal for use with non-Latin character sets.