100+ Employees? Well, my current environment is about 500,000 users across 3 campuses, and 4 domains. Throw in federated authentication (shibboleth), custom a

100+ Employees? Well, my current environment is about 500,000 users across 3 campuses, and 4 domains. Throw in federated authentication (shibboleth), custom apps, *nix auth, etc. With that in mind: It just works! With any large deployment (100 users isn't large) there are bound to be difficulties. That isn't the exclusive realm of Microsoft. As mentioned elsewhere, have you ever done a large deployment of kerberos? I have. I'll take AD on the infrastructure side any day. "Sideways" AD is a whole lot easier to manage than a sideways MIT Kerberos5 KDC. Microsoft does have its place. In the enterprise, in the server room, today.