Yahoo!
Yahoo grew rapidly throughout the 1990s. Yahoo went public in April 1996 and its stock price rose by 600 percent within two years. Like many search engines and web directories, Yahoo added a web portal, putting it in competition with services like Excite, Lycos and America Online. By 1998, Yahoo was the most popular starting point for web users, and the human-edited Yahoo Directory the most popular search engine, receiving 95 million page views per day which was triple the number compared to rival Excite. It also made many high-profile acquisitions. Yahoo began offering free e-mail from October 1997 after the acquisition of RocketMail, which was then renamed to Yahoo! Mail. In 1998, Yahoo! decided to replace AltaVista as the crawler-based search engine underlying the Directory with Inktomi. Yahoo's two biggest acquisitions were made in 1999 - that of Geocities for $3.6 billion, and Broadcast.com for $5.7 billion.
Outlook.com
Hotmail was sold to Microsoft in December 1997 for a reported $400 million, and it joined the MSN group of services. Hotmail quickly gained in popularity as it was localized for different markets around the globe, and became the world's largest webmail service with more than 30 million active members reported by February 1999.
Hotmail originally ran on a mixture of FreeBSD and Solaris operating systems. A project was started to move Hotmail to Windows 2000. In June 2001, Microsoft claimed this had been completed; a few days later they retracted and admitted that the DNS functions of the Hotmail system were still reliant on FreeBSD. In 2002 Hotmail still ran its infrastructure on UNIX servers, with only the front-end converted to Windows 2000. Later development saw the service tied with Microsoft's web authentication scheme, Microsoft Passport (now Microsoft account), and integration with Microsoft's instant messaging and social networking programs, MSN Messenger and MSN Spaces (later Windows Live Messenger and Windows Live Spaces, respectively).