If you are looking to create a fully-integrated online community with a single login for your users, I suggest you give Drupal a long look. While it does have a few shortcomings when it comes to its forum management, swift improvements are being made. This is one of those situations where the whole is greater than the sum of its parts and the future ahead looks quite bright.

The current version of Drupal can host forums which can be grouped according to administrator-defined categories. There is also a module available for sending and receiving private messages. Best of all, Drupal has one of the slickest, sturdiest, and easiest to install chat modules I’ve ever used.

Sure, you can paste different pieces of management software together in an unnatural manner, but do you really want to increase the threats to your security? If you want full site integration, I suggest you go for true site integration and use management software designed from the ground up with security in mind first and foremost.