Yesterday (April 8, 2014) was the last day of Microsoft's public support for Windows XP.
Windows XP was launched on October 25 2001 and still accounts for more than 25% of the installed operating systems in 2014 according to NetMarketshare. (You can tell by the screenshot; these are my last Windows XP patches.)
13 years ... not bad.
So long, Windows XP, we knew ye well.