William Slawski has compiled two very useful lists of acquisitions, first by Google and now by Yahoo (see also The Guardian’s list). I’ll add the third, Microsoft’s
as listed on their corporate site. From 2003 on:

Nov. 3, 2005: FolderShare 

Nov. 3, 2005: media-streams.com AG 

Aug. 30, 2005: Teleo Inc. 

Jul. 20, 2005: FrontBridge Technologies 

Mar. 10, 2005: Groove Networks Inc. 

Feb. 8, 2005: Sybari Software Inc. 

December 16, 2004: GIANT Company Software 

April 26, 2004: ActiveViews 

April 30, 2003: PlaceWare 

Feb. 19, 2003: Connectix

The crucial one there was Groove, which Microsoft acquired on March 2005. It seems to
have acted as a catalyst for their ‘software as a service’ strategy – Groove CEO and now
Microsoft CTO Ray Ozzie has been a leading light in that. Microsoft’s acquisitions
history suggests they strip off the technologies and human assets from their acquisitions
and put them into Microsoft products. Not dissimilar to what Yahoo and Google do nowadays

I’d say Yahoo’s key acquisitions over the past few years have been Overture (search),
Oddpost (email), Ludicorp/Flickr (social software street cred). You can definitely see a
pattern to all of Yahoo’s purchases, because they usually get eventually re-branded and
folded into the Yahoo business as part of their wide and deep product line. Overture
products for instance are now Yahoo! Search products. Oddpost has morphed into Yahoo’s
Gmail competitor, the new-look AJAX-driven Yahoo! Mail. And Flickr’s presence is being
felt across the board, in products such as My Web 2.0 and Yahoo 360.

Google is a bit harder to figure out, because as Adam Rifkin
a couple of months ago, Google tends to buy “small, creative,
engineering-driven teams with no-bullshit cultures and interesting products and/or
innovative technologies”. Maybe the difference comes down to semiotics, as
Ben Barren wrote

“Yahoo’s M+A semiotics read : fun, jagged, dangerous in the same way a rollercoast
ride is; delicious, flickr, konfabulator (sadly renamed) Google’s scrip semiotics are
more complex, obtuse, asexual + asynchronous : Android, Akwan, Urchin, Keyhole.”

Whatever the outcome of all these acquisitions, expect more to come in
2006. Already people are talking about a Microsoft/Newsgator deal, Yahoo/Netflix,
Yahoo/CNET, Yahoo/TiVo. And what about Google/Feedburner? (a shock pick suggested to me by one of my