A lot of different languages are available for the Back-end, but by default this language may not be installed. If you want a translated Back-end, get your language pack and install it using the Extension Installer. After this, go to the Extensions Menu, select Language Manager and make your language the default one. Your Back-end will be translated immediately.
Users who have access rights to the Back-end may choose the language they prefer in their Personal Details parameters. This is of also true for the Front-end language.
A good place to find where to download your languages and localised versions of Joomla! is Translations for Joomla! on JED.
Native RTL support means that every elements on the page is mirror swapped including layout, menus, typography, icons...everything.
In addition to comprehensive documentations in PDF format, you also get support from friendly forum and dedicated support system.
JSN Epic provides unique mechanism of installing sample data on directly your current website. Just few clicks and the demo website is here.