What Is Linux; Key Features - HP Armada 7400 Software Installation Manual

Installation of Linux on Compaq Armada 7400/7800 Portables

What is Linux?

Since its inception in the early nineties, Unix-based Linux has been highly visible in the academic and research
community, used primarily for e-mail, web servers and bulletin boards. With the source code and the operating system
freely available over the Internet and potentially twelve million users worldwide, there is evidence that Linux may be in
the process of gaining acceptance for commercial applications. This is further substantiated by the fact that leading
companies such as Oracle, SAP, Informix, Sybase and software vendors like Netscape, Corel, and Computer Associates
have ported their applications to Linux or are planning to do so. Compaq' s participation in joint projects over the last
four years has also contributed significantly to the Linux marketplace.
Linux is an independent POSIX (Portable Operating System Interface) implementation and includes true multitasking,
virtual memory, shared libraries, demand loading, proper memory management, TCP/IP networking, and other features
associated with Unix-type operating systems. Linus Torvalds, at that time a student at the University of Helsinki in
Finland, initially developed Linux in 1991. He continues to be one of the primary developers of Linux enhancements.
While Linux refers to the kernel of the operating system – the part that controls hardware, manages files, separates
processes, and so forth – it can also refer to the entire operating system built around the Linux kernel. A number of
companies, such as RedHat, Caldera, S.u.S.E., and Slackware have taken the freely distributed source code of the Linux
kernel, created documentation, installation procedures, and packaging, and tailored their own versions toward a specific
target audience. These companies' versions of Linux are commonly referred to as distributions.
The source code for Linux was developed under the GNU
freely available to anyone within the restrictions of that license. Linux distribution providers may give away or sell
copies, as long as the source code remains available. Because of the nature of the GPL to which Linux is subject, the
Linux kernel is still free as of its version 2.2.

Key Features

Linux has most major features and subsystems of a modern-day Unix operating system, including (but not limited to)
NFS, TCP/IP, X-Windows, send-mail, BIND, shell command-line interpreters, editors, and other tools that the Unix
market expects. Additionally, Linux has a large amount of Microsoft compatibility in the form of file system support,
PCX networking, and floppy management utilities.
The following are a subset of the Linux features:
§ Multitasking: several programs running at the same time
§ Multi-user: several users on the same machine at the same time
§ Multi-platform: runs on many different CPUs, not just Intel
§ Multiprocessor: Symmetric Multi-Processing (SMP) support is available on the Intel and SPARC platforms
§ Multithreading: Linux has native kernel support for multiple independent threads of control within a single process
memory space
§ Source code for the kernel, drivers, development tools and user programs is available and can be freely distributed
§ Multiple virtual consoles: several independent login sessions through the console
§ Supports several common file systems including Minix, Xenix, and all the common system V file systems as well as
an advanced file system of its own, which supports large volumes (up to 4 TB) and long file names (up to 255
characters)
§ Transparent access to MS-DOS partitions (or OS/2 FAT partitions)
§ Special file system called UMSDOS which allows Linux to be installed on a DOS file system
§ CD-ROM file system which reads all standard CD-ROM formats
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The GNU project, initiated for the Free Software Foundation by Richard Stallman, has the goal of writing a Unix compatible-operating environment
without reverse engineering.
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{means "Not Unix", GNU Public License (GPL)} and is
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