The most common editions of the operating system are Windows XP Home Edition, which is targeted at home users, and Windows XP Professional, which offers additional features such as support for Windows Servers, domains and two physical processors, and is targeted at power users, business and enterprise clients. Windows XP Media Center Edition has additional multimedia features enhancing the ability to record and watch TV shows, view DVD movies, and listen to music. Windows XP is known for its improved stability and efficiency over the 9x versions of Microsoft Windows. Windows X64-bit Edition for IA-64 (Itanium) processors and Windows XP Professional x64 Edition for x86-64 There is also Windows XP Embedded, a componentized version of the Windows XP Professional, and editions for specific markets such as Windows XP Starter Edition.
VISTA

Windows Vista is a line of operating systems developed by Microsoft for use on personal conclusions including home and business desktops, laptops, Table PCS, and Media Center PCs. Prior to its announcement on July 22, 2005, Windows Vista was known by its codename “Longhorn.”[4]Development was completed on November 8, 2006; over the following three months it was released in stages to computer hardware and software manufacturers, business customers, and retail channels. On January 30, 2007, it was released worldwide, and was made available for purchase and download from Microsoft’s website. The release of Windows Vista came more than five years after the introduction of its predecessor, Windows XP, the longest time span between successive releases of Microsoft Windows desktop operating systems. Windows Vista contains many changes and new features, including an updated graphical user interface and visual style dubbed Windows Aero, improved searching features, new multimedia creation tools such as Windows DVD Maker, and redesigned networking, audio, print, and display sub-systems. Vista also aims to increase the level of communication between machines on a home network, using peer-to-peer technology to simplify sharing files and digital media between computers and devices. Windows Vista includes version 3.0 of the .NET Framework, which aims to make it significantly easier for software developers to write applications than with the traditional Windows API.
UBUNTU

Ubuntu is composed of free and open source software distributed under various licenses, especially the GNU General Public License so that users are free to run, copy, distribute, study, change and improve the software. Ubuntu is sponsored by the UK based company Canonical Ltd, owned by South African entrepreneur Mark Shuttleworth. Instead of selling Ubuntu for profit, Canonical creates revenue by selling technical support. By keeping Ubuntu Free software and open source, Canonical is able to take advantage of the talents of outside developers in Ubuntu’s constituent components without developing the entire operating system itself.
BeOS

was an operating system for personal computers which began development by Be Inc. in 1991. It was first written to run on BeBox hardware. BeOS was optimized for digital media work and was written to take advantage of modern hardware facilities such as symmetric multiprocessing by utilizing modular I/O bandwidth, pervasive multithreading, preemptive multitasking and a custom 64-bit journaling file system known as BFS. The BeOS GUI was developed on the principles of clarity and a clean, uncluttered design. The API was written in C++ for ease of programming. It has POSIX compatibility and access to a command line interface through Bash, although internally it is not a Unix-derived operating system.
Mac OS X

is a line of computer operating systems developed, marketed, and sold by Apple Inc., and since 2002 has been included with all new Macintosh computer systems. It is the successor to Mac OS 9, the final release of the “classic” Mac OS, which had been Apple’s primary operating system since 1984. Mac OS X, whose “X” represents the Roman numeral for “10″ and is a prominent part of its brand identity, is a Unix-based operating system,[4] built on technologies developed at NeXT between the second half of the 1980s and Apple’s purchase of the company in early 1996. Its sixth and most recent version, Mac OS X v10.5 is certified UNIX 03 while running on Intel processors.
The first version released was Mac OS X Server 1.0 in 1999, and a desktop-oriented version, Mac OS X version 10.0 followed in March 2001. Releases of Mac OS X are named after big cats; for example, Mac OS X v10.5 is usually referred to by Apple and users as “Leopard”. The server edition, Mac OS Server, is architecturally identical to its desktop counterpart, and includes tools to facilitate management of workgroups of Mac OS X machines, and to provide access to network services. These tools include a mail transfer agent, a Samba server, an LDAP server, a domain name server, and others. It is pre-loaded on Apple’s Xserve server hardware, but can be run on most of Apple’s computer models.



