Release 5.0.20 has been published on March 9, 2017
Please read the ILIAS 5 features report for information about major changes and new features of this version.
Information about first time installation can be found here.
Before upgrading an ILIAS installation of version 3.9 or lower to 5.0 you will need to upgrade to 3.10 first. Instructions for updating ILIAS can be found in section 3 of the general installation instructions. For major updates (e.g. 4.3.x -> 4.4.x) the safest proceeding is, to upgrade a copy of your productive system first and test whether everything works ok.
If you use a customized skin/style, please change the skin settings for root user and default of installation to ‘delos‘ before upgrading from a 4.x version to 5.0.x. Otherwise you may not login any more due to templates changes in 5.0.