Scripts of social networks

https://www.drupal.org

This CMS is usually chosen by those who need a very big Internet project.
The control panel is much more complicated, but also more functional, which is suitable for a corporate network.
Many tools for managing a unified database of users.

Thousands of plug-ins that will add a system of blogs, forums. Drupal has its very good forum where you can help each other to learn and use CMS to the maximum.

But as for those, the choice is not great, so it will be necessary to try or contact others, here the forum will help.