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.
History of Gmail
Gmail was a project started by Google developer Paul Buchheit, who had already explored the idea of web-based email in the 1990s, before the launch of Hotmail, while working on a personal email software project as a college student. Buchheit began his work on Gmail in August 2001. At Google, Buchheit had first worked on Google Groups and when asked "to build some type of email or personalization product", he created the first version of Gmail in one day, reusing the code from Google Groups. The project was known by the code name "Caribou", a reference to a Dilbert comic strip about Project Caribou.