I\'m vaguely aware that on a computer joined to a domain IE can be asked to send some extra headers that I could use to automatically sign on to an application. I\'ve got ap
One option for you is to use CAS (central authentication service).
It has php client library.
How-to link to MS Active Directory: http://www.ja-sig.org/wiki/display/CASUM/Active+Directory
You would require Apache maven 2 though.