Linux: Encyclopedia II - Linux - History

Linux - History

In 1983, Richard Stallman founded the GNU project, which today provides an essential part of most Linux systems (see also GNU/Linux, below). The goal of GNU was to develop a complete Unix-like operating system composed entirely of free software. By the beginning of the 1990s, GNU had produced or collected nearly all of the necessary components of this system—libraries, compilers, text editors, a Unix-like shell, and other software—except for the lowest level, the kernel. The GNU project began developing their own kernel, the Hurd, in 1990 (after an abandoned attempt called Trix). According to Thomas Bushnell, the initial Hurd architect, their early plan was to adapt the BSD 4.4-Lite kernel and, in hindsight, "It is now perfectly obvious to me that this would have succeeded splendidly and the world would be a very different place today" [1]. However, due to a lack of cooperation from the Berkeley programmers, Stallman decided instead to use the Mach microkernel, which subsequently proved unexpectedly difficult, and the Hurd's development proceeded slowly.

Meanwhile, in 1991, another kernel — eventually dubbed "Linux" — was begun as a hobby by Finnish university student Linus Torvalds while attending the University of Helsinki. Torvalds originally used Minix, a simplified Unix-like system written by Andrew Tanenbaum for teaching operating system design. However, Tanenbaum did not permit others to extend his operating system, leading Torvalds to develop a replacement for Minix. Linux started out as a terminal emulator written in IA-32 assembler and C, which was compiled into binary form and booted from a floppy disk so that it would run outside of any operating system. The terminal emulator was running two threads: one for sending and one for receiving characters from the serial port. When Linus needed to read and write files to disk, this task-switching terminal emulator was extended with an entire filesystem handler. After that, it gradually evolved into an entire operating system kernel intended as a foundation for POSIX-compliant systems. The first version of the Linux kernel (0.01) was released to the Internet on September 17, 1991, with the second version following shortly thereafter in October [2]. Since then, thousands of developers from around the world have participated in the project. Eric S. Raymond's essay The Cathedral and the Bazaar discusses the development model of the Linux kernel and similar software.

By the 0.01 release, Linus had implemented enough POSIX system calls to make Linux run the GNU Bash shell; after this bootstrapping procedure, development accelerated rapidly. A computer running Minix was originally necessary in order to configure, compile, and install Linux. Initial versions of Linux also required an operating system to be present in order to boot from a hard disk, but soon there were independent bootloaders, the most well known being lilo. The Linux system quickly surpassed Minix in functionality; Torvalds and other early Linux kernel developers adapted their kernel to work with the GNU components and user-space programs to create a complete, fully functional, free operating system.

Today, Torvalds continues to direct the development of the kernel, while other subsystems such as the GNU components are developed separately. The task of producing an integrated system, which combines all of these basic components along with graphical interfaces (such as GNOME or KDE, which in turn are based on the X Window System) and application software, is now performed by Linux distribution vendors / organizations.

Tux the penguin is the logo and mascot of Linux (although there are other, less common representations; see OS-tan), based on an image created by Larry Ewing in 1996.

The name "Linux" was coined, not by Torvalds, but by Ari Lemmke. Lemmke was working for the Helsinki University of Technology (TKK), located in Espoo near Helsinki, as an administrator of ftp.funet.fi, an FTP server which belongs to the Finnish University and Research Network (FUNET), which has numerous organizations as its members, amongst them the TKK and the University of Helsinki. He was the one to invent the name Linux for the directory from which Torvalds' project was first available for download [3]. (The name Linux was derived from Linus' Minix.) The name was later trademarked (see below). Originally, Linus was going to call it Freax for "free" and with the often-used X in the names of Unix-like systems.

Linux - Licensing

The Linux kernel, along with most of the GNU components, is licensed under the GNU General Public License (GPL). The GPL requires that all source code modifications and derived works also be licensed under the GPL, and is sometimes referred to as a "share and share-alike" (or copyleft) license. In 1997, Linus Torvalds stated, "Making Linux GPL'd was definitely the best thing I ever did." [4] Other subsystems use other licenses, although all of them share the property of being free/open-source; for example, several libraries use the LGPL (a more-permissive variant of the GPL), and the X Window System uses the permissive (non-copyleft) MIT License.

The Linux trademark (U.S. Reg No: 1916230) is owned by Linus Torvalds, registered for "Computer operating system software to facilitate computer use and operation." The licensing of the trademark is now handled by the Linux Mark Institute (LMI). LMI has also sought to enforce the Linux trademark in countries other than the US. In September 2005, Intellectual Property Australia, the trademark regulator in Australia, rejected an application to trademark Linux.

Linux - Pronunciation

Linux is commonly pronounced either to rhyme with minix [ˈlɪnəks], or to rhyme with my nicks [ˈlaɪnəks]. The first pronunciation is considered more correct, while the second has become popular for sounding more natural in English. Other variations are also possible, but less frequently heard.

In 1992, Torvalds explained [5] (IPA pronunciations added to quote in braces):

An audio file of Torvalds saying "Hello, this is Linus Torvalds, and I pronounce Linux as /linəks/" also exists [6]. Note that in English, "Linux" and "Minix" are usually pronounced with a short /I/ sound that is different from Torvalds's Finland-Swedish pronunciation of these words.

See also List of words of disputed pronunciation for a discussion of the various ways "Linux" is pronounced.

Linux - Linux and GNU/Linux

Because the GNU libraries and programs, an essential part of nearly all Linux distributions, stem from a long-standing free operating system project that predates the Linux kernel, Richard Stallman and the Free Software Foundation ask that the combined system (regardless of distribution) be referred to as GNU/Linux or a Linux-based GNU system. Torvalds, the creator of the Linux kernel, has said that he finds calling Linux in general GNU/Linux "just ridiculous." Still, some distributions do use this name — notably Debian GNU/Linux — while most people simply refer to the system as Linux. The distinction between Torvalds' kernel and entire Linux-based systems that contain the kernel is a perennial source of confusion, and the naming remains controversial.

Linux - Litigation

In March 2003, the SCO Group (SCO) filed a lawsuit against IBM claiming that IBM had contributed some portions of SCO's copyrighted code to the Linux kernel in violation of IBM's license to use Unix. Additionally, SCO sent letters to a number of companies warning that their use of Linux without a license from SCO may be actionable, and claimed in the press that they would be suing individual Linux users. This controversy has involved lawsuits by SCO against Novell, DaimlerChrysler (partially dismissed in July, 2004), and AutoZone, and by Red Hat and others against SCO.

To date, no proof of SCO's claims of copied code in Linux has been provided and SCO's claims have varied widely. A few of Novell's press releases seem to demonstrate serious problems with SCO's claims:

• 2003-May-15 Novell Statement on SCO Contract Amendment (good news for Linux users)
• 2003-May-28 Novell Challenges SCO Position, Reiterates Support for Linux
• 2003-May-30 Novell Statement re: SCO press conference allegations
• 2003-Jun-06 Novell Statement on SCO Contract Amendment
• 2003-Nov-18 Novell Statement on SCO claims regarding a non-compete clause in Novell-SCO contracts

The most comprehensive coverage of this suit is given by Groklaw.

Adapted from the Wikipedia article "History", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki