History of Yahoo!
On March 8, 1997, Yahoo! acquired online communications company Four11. Four11's webmail service, Rocketmail, became Yahoo! Mail. Yahoo! also acquired ClassicGames.com and turned it into Yahoo! Games. Yahoo! then acquired direct marketing company Yoyodyne Entertainment, Inc. on October 12, 1998. In January 1999, Yahoo! acquired web hosting provider GeoCities. Another company Yahoo! took over was eGroups, which became Yahoo! Groups in June 2000. On March 8, 1998, Yahoo! launched Yahoo! Pager, an instant messaging service that was renamed Yahoo! Messenger a year later.
Oddpost
Oddpost was a pay-for webmail service, in 2002, that pioneered the use of JavaScript to mimic a desktop mail application, the first notable foray into using Ajax methodologies for webmail. Ajax techniques minimized the amount of data sent during an email session by sending "Datapacks" instead of reloading the whole interface on every click like a traditional webmail service (Hotmail, AOL). This made the service much faster, at the time, than its counterparts.