The easiest way is the following. It’s used by TinyMCE and CKEditor and many others. There are many variations: in particular, if you are creating a code editor, there are clever tricks you can do using textareas and a monospaced font. Dynamically create an iframe and place the editable content within that iframe’s document Set … Read more
Most rich text editors for the web use JavaScript. These are some popular ones you could consider jwysiwig markitup Redactor (This is great jQuery based wysiwyg editor that also has a Rails extension I’ve linked to below.) Bootstrap-wysihtml5 (If you’re looking for a Twitter Bootstrap style editor) Of course, you could also consider heavy-weight alternatives … Read more
You could start with the Ace editor (formerly Bespin and Skywriter). It’s aimed at code editing, so it’s missing formatting and other features, but you may find a useful core of functionality to base a rich text editor on. In action: http://ajaxorg.github.com/ace/build/editor.html Code: https://github.com/ajaxorg/ace Update: As @theazureshadow points out, the current editor doesn’t use canvas … Read more