TinyMCE - TinyMCE is a content editor that functions as a plug-in for Wordpress websites.
Big Huge Labs Writer - Writer is a free online distraction free writing environment provided by Big Huge Labs.
Amaya - Amaya is a web editor that is used for creating and updating the documents directly on the websites.
Caret - Better Markdown Editor for Mac / Windows / Linux
Summernote - Summernote is a JavaScript library that helps users create WYSIWYG editors online.
Office Online - With Office Online you can view, edit, and share Word, Excel, PowerPoint, and OneNote files on your devices using a web browser, so you can work anywhere.