Yes, Virginia, There Is Still LDAP

With the current trend of adapting web-based single-sign-on solutions, it is easy to forget about one of the most prominent authentication and user information systems still in use: LDAP.

At its base, LDAP is a collection of objects that:

1. have a Distinguished Name to identify them,
2. have attributes that follow predetermined schema, and
3. are structured and related to each other as nodes on a branching tree.

The above properties affect how you identify and manipulate them.