It took Microsoft's $44.6 billion bid, and the interest of News Corp. and Time Warner’s AOL, to remind the world that Yahoo is still an internet powerhouse. Founded in 1994 by Stanford students David Filo and Jerry Yang, Yahoo attracted almost 139.5 million unique visitors to its sites in March, about 2 million more than its archrival, Google, and its ads reached 85 percent of all Web users, compared with Google’s reach of 81 percent. Yet Google performed 60 percent of all Web searches—Yahoo executed 22 percent—which explains why it took in revenue of $16.6 billion last year, against Yahoo’s $7 billion. Still, the 50 companies Yahoo has amassed, for more than $25 billion in cash and stock, represent an enormous community of Web users—one that Microsoft has desperately sought.

1997 The $92 million purchase of Four11 provided Yahoo with free email technology. Yahoo also bought Net Controls, whose software built stock, weather, and sports toolbars.

1998 Yahoo got into multiplayer online games by buying Classic Games. It spent $49 million for Viaweb, letting users create online stores, and $30 million to buy ad network Yoyodyne.

1999 Yahoo spent $5.7 billion on Broadcast.com, for streaming on-demand audio and video, and $3.6 billion on GeoCities, to advance the online-community concept.

2000 Buying eGroups for $432 million extended Yahoo’s group-email-list services. Buying Taiwanese portal Kimo for about $135 million built its Asian presence.

2001 After the dotcom meltdown, Yahoo bought auction site Sold.com.au for about $16 million and streaming-content company Launch Media for $12 million.

2002 Yahoo acquired job-search ­marketplace HotJobs for $436 mil­lion and Web-search software company Inktomi for $235 million.

2003 Overture, bought for $1.63 billion, established the pay-for-performance ad model of translating search-engine results into dollar figures.

2004 Yahoo purchased European comparison-shopping site Kelkoo for $570 million to combat Google’s now-defunct Froogle, and Musicmatch for $160 million in an attempt to fight RealNetworks and Apple’s iTunes.

2005 Yahoo spent $1 billion in cash for 40 percent of Chinese auction site Alibaba and picked up bookmarking application del.icio.us and photo-sharing site Flickr.

2006 The company bought Swedish mobile-media provider Kenet Works and Taiwanese blogging service Wretch, each for $22 million.

2007 Yahoo spent $650 million to buy the 80 percent of online-ad exchange Right Media that it didn’t already own, and paid $300 million for ­online-ad network Blue Lithium.

2008 On the eve of Microsoft’s hostile bid, Yahoo acquired Israel-based music-player plug-in FoxyTunes and, for $160 million, broadband-video channel Maven Networks.

-- Additional reporting by Stacy McIntyre