On this day in 2001 the Windows XP operating system was officially released for retail sale. It was produced by Microsoft as part of their Windows NT family of operating systems, succeeding the Windows 2000 Professional and Windows ME. It was built on the Windows NT kernel and designed specifically for mainstream consumer use.
Upon its release the Windows XP received generally positive reviews, with critics noting several improvements from its predecessors, such as increased speed, a more intuitive UI, and expanded multimedia capabilities. By January 2006 over 400 million copies were already in use, reaching a total of over a billion by April of 2014.
Windows XP was eventually succeeded by Windows Vista, and support and security updates for it ceased by 2014. As of August 2017 however market shares indicate that Windows XP is still the fourth most popular Windows version after Windows 7, 10 and 8.1.
