BSD

Linux

Minix

GNU/Hurd

Plan 9

Solaris

OpenVMS

OS X

AIX

HP-UX

Windows

Windows is an operating system developed by Microsoft under the leadership of

Bill Gates.

Versions of the Operating system include Windows95, Windows XP, Windows Vista and currently Windows 7. Windows is closed source, proprietary and expensive. Aside from buying the operating system, it is also necessary to obtain virus-prevention software when using the operating system on the internet. Microsoft now offers its own free virus prevention software, Microsoft Security Essentials. Microsoft has a market share majority and many popular programs are only available in Windows. Even though most programs have alternatives that are of equal or superior functionalality Microsoft versions remain dominant due to marketing practices, brand recognition, and vendor lock-in.

Microsoft also releases server versions of their operating systems. Versions include Windows NT, Windows Server 2000, Windows Server 2003 and currently Windows Server 2008. Microsoft Security Essentials is mainly meant for client systems and servers may need to purchase more robust anti-virus and security software. The main appeal for running a Windows server/network are their directory services, Active Directory. Active Directory provides centralized control of most network functions through Domain Controllers. Network storage, printers and other devices, users and groups, computers, and updates can all be managed from Domain Controllers.

Some of the well known symbols for Windows are the Windows Icon and the MSN butterfly, seen below.