1. Microsoft Windows
The Microsoft Windows family of operating systems originated as a graphical layer on top of
the older MS-DOS environment for the IBM PC. Modern versions are based on the newer
Windows
NT core that first took shape in OS/2 and borrowed from OpenVMS. Windows runs on 32-bit
and
64-bit Intel and AMD computers, although earlier versions also ran on the DEC Alpha, MIPS,
and
PowerPC architectures (some work was done to port it to the SPARC architecture).
As of 2004, Windows held a near-monopoly of around 90% of the worldwide desktop market
share,
although this is thought to be dwindling due to the increase of interest focused on open source
operating systems. [1] It is also used on low-end and mid-range servers, supporting
applications
such as web servers and database servers. In recent years, Microsoft has spent significant
marketing and R&D money to demonstrate that Windows is capable of running any enterprise
application (see
the TPC article).