Mainframe / Server operating systems (multi-user)

Split between UNIX/Linux and Microsoft. Been that way for a long time.

Usage share of server operating systems, 2008.
Stats from IDC Server Tracker.
Pie chart generated with piecolor.com.

• Update: End 2010. Server OS share (by percentage of revenue):
  • Windows 42.1
  • Unix 25.6
  • Linux 17.0
  • z/OS 11.3
  • Other 4.0

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Server operating systems

• mainframes / servers (multi-user),
  file servers (shared filespace in LAN),
  web servers

• UNIX / Linux
• Windows Server
• z/OS
• VM
• VMS

• IDC Server Tracker report, 2008 shows market share:
  1. Windows - 36.5%
  2. UNIX - 32.7%
  3. Linux - 13.4%
  4. z/OS - 11.8%
  And search for updates.