I need to create a web app that will be accessed by employees. We run dual platform W2K and Mac OS.

Our apps will use IIS 5, Sql Server 2K and Active Directory. All employees have a domain account in Active Directory. We use Windows authentication with Sql Server.

What would be the best form of authentication? I would want the windows users to automatically be authenticated without the user entering information. I would want MAC users to enter their username and password once and not need to enter it again.

Anynomus access is turned off on IIS and the web config file has deny unknown users. How does Passport authentication work? Is the information stored on the server, local machine? how does it work with non windows OS?

Thanks for your advice.