Recently I was doing some consultancy work and they need to authenticate users using Active Directory service. However you need to compile Apache web server to add LDAP bindings. Apache LDAP allows an LDAP directory to be used to store the database for HTTP Basic authentication.
Next load LDAP module, configure directory security and you are done.
You don’t have to install and use samba package 🙂
There is a good howto that explains configuration parameters and other stuff.
How to Configure Apache Authentication with Active Directory