LanguageTool
Free proofreading tool for OpenOffice, LibreOffice, Firefox, and Chrome. Also available as a standalone application. Supports about 20 languages (on different levels) and allows customization.
FreeSpell is a spell checker for any and all Windows applications. You can use it in Microsoft Outlook, Firefox, Visual C++, and even in Windows Explorer when renaming...
freespell is a spell checker for any and all windows applications. you can use it in microsoft outlook, firefox, visual c++, and even in windows explorer when renaming files. in fact, anything that supports the clipboard supports freespell, and all it takes is a hotkey to invoke it. freespell is based upon the aspell engine, which means it offers the best spell checker around for people with weak spelling skills (as well for people who just need a quick proofread). freespell comes with a large default dictionary and has custom dictionary support.
Free proofreading tool for OpenOffice, LibreOffice, Firefox, and Chrome. Also available as a standalone application. Supports about 20 languages (on different levels) and allows customization.
Freemium
Ginger Keyboard is the world’s first smartphone keyboard to offer advanced writing tools, including live as-you-type proofreading, alongside standard and advanced keyboard features like word prediction, autocorrect, emoji and swipe typing.
Freemium Windows Android iPhone Android Tablet iPad Chrome OS
Whether you’re writing a letter or an email, a simple click of a button will open some of the most comprehensive and useful language resources ever created.
Commercial
Grammar & Spelling Check; Free Online Proofreading; No Downloads...Allows you to find those pesky mistakes and correct them before your teacher does...
Freemium Web
This is a grammar checker that correct mistakes in your writing.
Freemium Android iPhone iPad Web
Spelling checker. Checks HTML, TeX/LaTeX, RTF, and ASCII (plain text). Hotkey spell checking in WordPad, Notepad, Email, browsers, etc.
Free Personal Windows
cocoAspell is Mac OS X interface to Aspell – A more intelligent Ispell – that is being developed by Kevin Atkinson. Aspell is an Open Source spell checker designed to...
Free Open Source Mac OS X
SpellCheckPlus is a grammar checker that finds common spelling errors and grammatical mistakes in English.
Freemium Web