aloha is a Javascript library which allows users to edit target html elements on a page.
aloha allows users to edit html tags. aloha needs to be included as a script into the page which is studied by it. Aloha can be initialized on certain html elements like this:
Aloha.jQuery(selector).aloha();
and then the user will be able to edit things, like this
Aloha has a lot of plugins, users can choose some plugins if they want to do so, see more here.