Froala wysiIwyg Joomla editor plugin
Download this repo, archive folders com_froala, plg_editors_froala, plg_system_froala to .zip and install archives using joomla extension Manager. To replace the current editor on Froala, go to Joomla General settings and in the tab “Site” select Froala as the default editor. So as you can assign an editor to a specific user.
This package is available under GPL v2 or later License. However, you have to purchase a license for Froala Editor from http://editor.froala.com/pricing.