JomSocial 4.4.0 is a huge milestone in the development cycle. It introduces features built from empty file and improves existing ones.
This is the short list of major features in JomSocial 4.4.0
New Feature Support for Joomla ACL
New Feature Real time chat as private messaging system
New Feature Migrators for Community Builder and EasySocial
Improvement Privacy improvements
For a raw, unedited changelog, please refer to this file