Directory Service: It offers system administrators, developers, and end users alike a consistent, efficient, and secure means for viewing and managing resources such as people, fles, printers, and applications.

The ldap_connect() function establishes a connection to an LDAP server identified by a specific host name and optionally a port number.

Prototype:

resource ldap_connect([stiring hostname[, int port]])

Example:

<?php
   $host="ldap.wjgilmore.com";
   $post="389";
   $connection=ldap_connect($host,$port) ro die("Can't establish LDAP connection");
?>

Web service: Web services are typically application programming interfaces (APIs) or web APIs that are accessed via Hypertext Transfer Protocol (HTTP) and executed on a remote system hosting the requested services.

RSS ( Really Simple Syndication) is a family of web feed formats used to publish frequently updated works—such as blog entries, news headlines, audio, and video—in a standardized format: XML.

Advantage:
1. The ability to treat software as a service.
2. Significantly imporved enterprise application integration (EAI) process.
3. Global reuseability.
4. Ubiquitous accessibility.