Introduction

Soon after ICQ andAIM (AOL Instant Messenger) gained popularity and amassed millions of users, Yahoo! built its ownproprietary instant messaging service. The client that Yahoo! released, Yahoo! Pager, had theability to connect to the AIM network. AOL, both with its AIM and ICQ services, had locked up themajority of instant messaging users. Since AIM and ICQ were operating on closed networks, and sincethey had signed up so many users, the only way someone could talk to an online contact was byeither using one of AOL s clients or by using a client that was compatible with these services thatallowed for communication with multiple networks. Yahoo! realized that the quickest way to buildtheir own user base for instant messaging was to build clients with the ability to connect with themajority of online instant messaging users, while at the same time connecting these users to theirown networks.

Interoperability did not last long, as AOL was quick to change its protocol in order torestrict access to its network, and after multiple fixes to the client and multiple changes toAOL s protocol, Yahoo! gave up on building multi-protocol clients, and focused on building its ownservice and increasing distribution of their own clients.

Yahoo! has also been successful in attracting users, and has been growing steadily since itsearly days when it was known as Yahoo! Pager. Its current version, Yahoo! Messenger, comparesfavorably with features of other instant messaging clients, and its ability to utilize manyfeatures of the Yahoo! Internet portal makes it a logical choice for...