Firefox doesn't have integrated Active Directory (AD) support. AD is useful generally in enterprises where there are thousands of machines and setting up web browser preferences on each one may be a tedious task. AD lets you set up group policies that Firefox should follow. For example, some policies may include setting the default home page, or setting the proxy settings based on user groups.

As of right now, it is hard for IT administrators to install Firefox remotely over the network. Certain tools exist to help them but there is very little in the way of customization on the browser itself. This is limiting Firefox's ability to get into large networks and companies where IE is more prevalent. My .msi compiler will allow an administrator to build a Firefox installer and push it over the network.