Best Rich Text Editor for web application having dynamic form with many text editor. 1)text editor can easily trnsform textarea 2)Light weight
SO uses WMD seems to work quite well.
CK Editor
Free textbox
http://www.asp.net/AJAX/AjaxControlToolkit/Samples/HTMLEditor/HTMLEditor.aspx
Nicedit
Will easily transform all you textareas (or just one)
Has occasional css-leakage problems (beacuse it doen't use heavy iframes)
Image upload works great, painlessly if you're willing to go through nicedit server. If you don't like that, you can roll your own. The built-in image uploader sticks images @ imageshack. Pretty slick.
It's easy/quick/dirty, but works in a lot of situations.
Casual need for WYSIWYG users seem to love it.
Assuming you are looking for a WYSIWYG editor.
jwysiwyg
is one based on jQuery.
CKEditor
is one with more options.
TinyMCE - Javascript WYSIWYG Editor
is also another option.
If you need a WYSIWYM editor then go for
WMD: The Wysiwym Markdown Editor
Cute Editor is one of the best but it isn't free. For Free I'd choose either FCKEditor or TinyMCE