Developer Garden Cloud User Management API

In addition to their telecom and marketplace API's, Developer Garden provides free to use "labs" API's such as their Cloud User Management web service.

This API allows developers and providers of Web applications to store user log-in data and profile information in the cloud. When integrated with multiple applications or websites, the Cloud User Management API functions as a single sign-in service for different applications or sites from a common provider. Users can also quickly create an account using a variety of third-party online identification providers, such as Google, Facebook, AOL, OpenID, and Yahoo!.