TinyMCE is an open source (under the GNU Lesser General Public License) rich-text editor released and maintained by Moxiecode. As indicated by the name, TinyMCE is lightweight but highly customizable through an intuitive API. TinyMCE’s plugin system allows you to download themes and plugins to extend the core installation.
2. FCK Editor
FCKeditor is another wildly popular open source online rich-text editor (check out some of the websites that use it). It has a “Word clean-up” feature that automatically detects and cleans up text that’s copied from Microsoft Word documents. It has one of the best HTML table editing and creation features, making it very easy for users to create and edit tables for displaying data.
BXE is an XML-based WYSIWYG editor that allows you to change an entire web page. It has been an open source application since 2002 – and with a devout following – you might be able to quickly find some help if you run into any issues in the BXE IRC channel.
8. Cross Browser Rich Text Editor (RTE)
Cross-Browser Rich Text Editor (”RTE” for short) is a free rich-text editor released under the Creative Commons Attribution 2.5 license. It’s a work based on the designMode functionality introduced in Internet Explorer 5 and implemented in the Mozilla Rich Text Editing API. It just has basic features, so it’s perfect for individuals looking to add simple rich-text editing support.
9. YUI Library Rich Text Editor
The YUI Library Rich Text Editor is a UI control that’s part of the YUI Library. It’s a great solution for those already using YUI and individuals that want to save some server resources (since you can serve it directly from the Yahoo! servers). The YUI Library Rich Text Editor also has excellent mobile device support, making it a great web-accessible rich-text editing solution.
11. Damn Small Rich Text Editor
Damn Small Rich Text Editor (DSRTE) is a lightweight, free rich-text editor built on top of the jQuery library and a PHP backend. It’s plugin-enabled (meaning it’s highly-extensible), has image-uploading capabilities (using Ajax for responsive user interaction), and an HTML cleanup feature to tidy up messy markup.
12. Silverlight Rich Text Editor
Silverlight rich text editor is the first rich-text editor for Silverlight. It has many useful features such as “find and replace” to quickly find specific text or to batch-replace them with something else, keyboard shortcuts support, serialization of text input for security, and much more. Note that the original creator has stopped further development (so cross your fingers someone picks up his project).
13. Free Rich Text Editor
WYMeditor is a web-based HTML editor that emphasizes the use of standards-compliant markup. It was developed to output compliant HTML 4.01 Strict Doctype HTML, so it’s the perfect solution for the standards-aware developer.
openWYSIWYG is a free and feature-packed web-based content editor that’s perfect for a host of content management systems. It has a very intuitive “table creation” feature to help users construct HTML tables. It also has a wide range of browser support including IE 5.5+ (Windows), Firefox 1.0+, Mozilla 1.3+ and Netscape 7+.
XStandard is a highly-standards-compliant rich-text editor. It comes in two versions: XStandard Lite – which is completely free, and XStandard Pro. XStandard Lite has Microsoft Word text cleanup, spellchecking, and the ability to interact with third-party applications.
Xinha is an open source, community-built rich-text editor released under a BSD style license. It’s highly-configurable, extensible, and feature-packed. Xinha emphasizes on community development, and as such, you’ll find many helpful contributors in the Xinha forums.
Kupu is an open source “document-centered” client-side rich-text editor released by the international association for Open Source Content Management (OSCOM). It features easy integration into a variety of content management systems including Silva and Plone, easy customization and extension, and Ajax saving for an uninterrupted user experience.