Also called the Passport Network, Microsoft Net Passport is a Web-based service that lets users of participating Web sites sign in using a single e-mail address and password. It removes the need for users to remember multiple login IDs and passwords. Windows Live ID also works with Passport Network sites.

.NET Passport is a Web-based service that is designed to make signing in to Web sites fast and easy. Passport enables participating sites to authenticate a user with a single set of sign-in credentials, alleviating the need for users to remember numerous passwords and user names.