Joomla! announce the release of Joomla! 3.5 as the latest in the 3.x series. Introducing 34 new features, including support for the recently released PHP 7 scripting language, which significantly increases web site speed.

More release note:
https://www.joomla.org/announcements/release-news/5654-joomla-3-5-is-here.html

Download link:
https://www.joomla.org/download.html

Upgrading from Joomla 3.4.x to 3.5:
https://docs.joomla.org/J3.x:Upgrading_from_Joomla_3.4.x_to_3.5

General upgrade:
https://docs.joomla.org/J3.x:Updating_from_an_existing_version

Technical Requirements:
https://www.joomla.org/about-joomla/technical-requirements.html