More than one user can be logged into a single computer at a time. This is a nice feature for the currently popular thin-client model that relies heavily on a central high capacity computer to host services and provide the processing power.
True preemptive multi-tasking enables the operating system core to efficiently juggle several running programs at once. This is important for providing multiple services on one computer.
Linux currently runs on Intel (or equivalent) based PC's, Digital/Compaq Alpha, PowerPC-based (Apple Macintosh), Sun Sparc, Amiga, StrongARM-based computers, many PDA’s and has recently been successfully ported to the S390 main frame, and larger projects such as super-computers and clusters are planned by certain academic organisations for the likes of environmental/ocean modeling. Tight budget constraints and the easy access to source code make Linux a clear, favourable choice.
Linux interfaces with most network protocol and operating systems and file structures, including MS windows and NT, Unix, Novell, and Mac OS.
As your computing needs grow, you can rely on Linux to grow with you. The Linux kernel is currently scalable to four processors, with a great deal of development taking place to increase this.
Linux is mostly written in the C programming language. C is a mid-level language, created specifically for writing system-level software that can be readily ported to new computer hardware.
The Linux operating system can be configured as required: A desktop workstation for an office, a home PC for games and word-processing and internet browsing or just as easily a company Web/FTP/print server or a network router/firewall or part of a corporate cluster. Most distributions already include these facilities and just need them selected.
Like its Unix ancestor Linux has achieved a reputation for stability unmatched by any other operating system. Most computers running Linux only ever need to be stopped for hardware changes. It is not uncommon for Linux computers to run for several years between downtime
The modular design of Linux enable the configuration of just the components needed to run the desired services. Older computers, 486 and even 386 can become useful again. E.G. the use of a 386 PC configured just as a network router/firewall.
The Kernel is the property of Linus Torvalds, but Linux is developed by enthusiasts in their own time, striving for purity and functionality. Although some companies do package and sell tailored distributions, It is possible to obtain Linux distributions for no exchange of money and in the case of Linux you do not necessarily get what you pay for. There is an active Linux community only to ready to help a newcomer. Charities and the third world may be very interested in Linux because of this.
A note by Chris Tyler