Who designed the Linux penguin

When Linus Torvalds put his Linux 0.01 on the Internet 20 years ago, he hit a nerve with the idea of ​​a free Unix clone that anyone can help develop. Nowadays, Linux has become an indispensable part of the IT world.

It has been twenty years since Linus Torvalds programmed the first lines of what would become the Linux kernel. At that time, the computer science student was not thinking of having his own operating system, but simply wanted to explore the capabilities of the 386 processor in his PC. The experiments with memory management, process switching and I / O eventually developed into something like a rudimentary operating system kernel.

For Torvalds, who used Andrew Tanenbaum's Unix-like teaching operating system Minix at home and knew Unix from university, it was clear that his own operating system had to be Unix-like. So in July 1991 he asked the Minix newsgroup about the POSIX standard, the definition of the Unix system interfaces. On August 25, 1991, Linus Torvalds sent a post afterwards in which he first mentioned that he was working on an operating system for the 386 ("just as a hobby, it won't get big and professional like GNU"), and the Minix community around Suggestions asked which features they would like to see.

Linux 0.01

On September 17, 1991 Torvalds finally made his "Linux 0.01" available for download on an ftp server (Torvalds wanted to call it "FreaX", but the ftp admin found the name "Linux" better). Linux 0.01 could hardly do anything: the kernel only ran on 386 processors, only supported the Finnish keyboard layout and only booted from floppy disk. It looked even darker with the applications: They were limited to the Unix shell bash and the GNU C compiler.

But Linux hit a nerve: a number of Unix fans, for whom the capabilities of Minix were too limited and Unix workstations too expensive, rushed to the new operating system, sent Torvalds their wishes, tinkered with drivers and ported their first programs. The basis for this was provided by the GNU project founded by Richard Stallman in 1984, which had programmed a large number of classic Unix tools in such a way that they could be translated on different Unix systems. The only thing missing for a complete operating system was the kernel, and that is what Linus Torvalds provided: GNU / Linux was born - in a form in which it has remained (on the command line) to this day.

In November 1991 Torvalds accidentally deleted the Minix partition on his PC and was faced with the choice of reinstalling Minix or developing Linux into a usable system. He chose Linux. In January 1992 he published Linux version 0.12 for the first time under the GPL; a decision that he - despite some differences of opinion with GPL author and FSF founder Richard Stallman - considers to be the right one to this day.

"Linux is obsolete"

At that time the Linux people met in the Minix newsgroup, but the computer science professor and Minix inventor Andrew Tanenbaum was annoyed by the increasing Linux discussions in the Minix forum. His famous posting "LINUX is obsolete" in January 1992 was followed by an exchange of blows with Torvalds; eventually the growing Linux community moved to its own newsgroup.

In 1992, the X Window System, which is still in use today, gave the Linux kernel 0.95, which, thanks to a virtual memory management system, could now swap data from RAM to disk, a graphical user interface. Now the kernel hackers tackled the network stack. The first SCSI and sound drivers, the Ext2 file system and the ELF format for binaries were implemented, the BSD printing system was ported, kernel modules that could be reloaded at runtime and the / proc pseudo file system were implemented. Linux became increasingly usable; In 1992 the first Linux distributions appeared with SLS and Yggdrasil. Slackware and Debian, launched in the spring and summer of 1993, still exist today.

In March 1994, Linux 1.0 appeared after a long series of 0.99.x versions and introduced a development mode that was to last for ten years: In parallel to the careful further development of the stable user kernel with an even version number (1.0), new features were added to a developer kernel ( 1.1), which starts with the code base of the user kernel and ultimately leads to a new major version.

The fact that Linux now runs on almost everything that can differentiate between zeros and ones, on embedded devices from routers to smartphones as well as on mainframes, has its roots in the Linux kernel 1.2. In March 1995 it brought numerous new drivers and improvements in the network area (IP forwarding, firewall, additional network protocols such as NFS) as a major innovation, the first porting to other processor architectures: Alpha, Mips and SPARC. Linux 1.2 thus laid the foundation for the several dozen platforms to which the Linux kernel has now been ported.

With improved network capabilities and applications such as Apache, Samba, and Sendmail, a market for Linux gradually emerged and was served by commercial Linux distributors such as Caldera, Red Hat, and Suse. Caldera has since disappeared from the scene (more on that in a moment), Suse was bought by Novell at the end of 2003 and has been independent again since it was acquired by Attachmate last year. Red Hat is likely to break the one billion US dollar mark for the first time this year.

Tux the penguin

But back to the Linux kernel. In June 1996 Linux 2.0 brought the first support for multiprocessor systems - and the mascot Tux designed by Larry Ewing. In March 1997, kernel.org was launched, which is still home to the official kernel sources and the Linux Kernel Mailing List (LKML), in which the kernel hackers discuss issues. In September 1998, while working on Linux 2.1, there was a solid row among the developers: Torvalds could not keep up with the installation of the patches sent to him in the kernel sources, many programmers were frustrated, and development threatened to split.

The situation could be defused, however, in that veteran developers like Alan Cox and Ted Y. Ts'o, acting as "pre-filters", relieved Torvalds of the work of checking every patch himself; an organization that has lasted to this day. In 2002 the "Linus does not scale" story repeated itself. This time, a technical solution was found in the more powerful source code management system Bitkeeper, which was replaced three years later by the version control system Git, which was written by Torvalds himself - now a standard in the open source world itself.

Linux 2.2 appeared in January 1999. The kernel now ran reasonably well on SMP machines with up to four processors, brought more efficient memory management, supported IPv6 and contained powerful firewall code - the gap to the commercial Unix competition had shrunk. Sound and video hardware has also been significantly better supported now.

In the two and a half years that it took to develop Linux 2.2, a lot had happened in user land: KDE and Gnome brought Linux graphical desktops with capabilities that went beyond the traditional X11 window managers. With StarOffice 3 and the Netscape Navigator, the forerunners of OpenOffice and the Mozilla programs appeared in Linux versions. Oracle and Informix ported their databases to Linux in 1998. The first Beowulf cluster of 68 alpha computers made it into the top 500 list of the fastest computers in the world in 1998 - today, Linux runs on over 80 percent of supercomputers.

In August 1998 Linus Torvalds shone on the cover of the American business paper Forbes: Linux and Open Source had become legally viable. Hardware manufacturers like Dell and Hewlett-Packard announced Linux servers. These developments brought Microsoft on the scene: In the Halloween papers, the company dealt with the new competition and their qualities and tried to find a strategy as an answer to Linux; in April 1999 the notorious Mindcraft study was supposed to prove the technical inferiority of Linux. In 2001 Microsoft then tried its hand at fundamental opposition: Linux was a cancer and open source was destroying intellectual property, according to Redmond.

The big hype

The big Linux hype

The bad sayings from Redmond couldn't stop PC-Unix, which had long outgrown its roots in the x86 architecture. IBM announced a major Linux initiative, and at CeBIT 1999, SAP granted the free operating system with a Linux Version of his ERP suite R / 3, so to speak, the accolade. The porting of Linux to the IBM mainframe S / 390 (today z-Series) at the end of 1999 once again proved the immense flexibility of the free operating system - quite a few analysts believe that Linux saved IBM's mainframe. The following year, the Suse Linux Enterprise Server was the first explicit corporate distribution - for IBM mainframes. The x86 version of SLES followed in 2001.

But Linux was also gaining popularity at the other end of the hardware spectrum: Compaq had already introduced a handheld computer called Itsy in 1998 that ran on Linux - the forerunner of today's Android smartphones and tablets, so to speak. In March 2000 the Embedded Linux Consortium (ELC) was founded with the aim of drafting a specification for Embedded Linux.

In general, the turn of the millennium was the time of the great Linux hype: In 1999, Red Hat was the first Linux company to have a brilliant stock market launch; the share quadrupled its value on the first day of trading (but later had to give up a lot after the .com bubble burst). The Linux Professional Institute LPI published its first distribution-independent Linux exam in 2000. In order to prevent Linux from repeating Unix history and splitting it into numerous incompatible Linux versions, the Free Standards Group was founded in the same year with the aim of creating a Linux standard (meanwhile the Free Standards Group - like the ELC - incorporated into the Linux Foundation). In December 2000, IBM announced that it would invest a billion US dollars in Linux in 2001.

With the 2.4 kernel, Linux entered the spheres of the commercial Unix variants at the beginning of 2001: powerful SMP operation with up to eight processors, 64 GByte RAM on x86 processors, raw devices, a 64-bit file system. Firewire and USB support, ACPI and Plug & Play for the ISA cards, which were still in use at the time, made the new kernel attractive for desktop and notebook use. Hardware manufacturers such as Intel and AMD are increasingly involved in Linux development: good Linux support became more and more important in the server business. In 2002, Red Hat launched its first Enterprise Linux.

The thing with the Linux desktop

With the increasing success of Linux, more and more companies and public administrations began to think about the advantages of open source software. In 2003, for example, Deutsche Bahn decided to use Linux as a strategic server platform - a decision that is still valid today. In the same year, the Munich city council decided to convert the 15,000 computers of the city administration to Linux desktops - in April of this year the mountain festival was celebrated: half of the computers were converted to the Munich LiMux client. The Foreign Office began introducing open source software as early as 2001, and desktops were switched to Linux in 2005 - but the project ultimately failed. The Linux desktops in the Stuttgart insurance group, which were rolled out in 2003, are still in use today.

But despite a few prominent examples: The Linux desktop was never able to establish itself on a broad front (Chris Schläger, head of the operating system laboratories at AMD, gives reasons in this article). The "Year of the Linux Desktop", which was proclaimed again and again until 2006 or 2007 and which was about to begin, did not take place. The dedicated desktop distribution Ubuntu could not change this either, which from 2004 onwards mixed up the Linux world, but could not really score against Windows. Linux is successful on the server - and on embedded devices. When Android, Google's smartphone and tablet system with Linux kernel, came onto the market in 2008, Linux had long been established in machine control, in WLAN routers, DVD players and navigation systems.

Basis for the future

In December 2003 the Linux kernel made the jump to version 2.6. This not only brought the security enhancement SELinux, a new device model accessible via Sysfs and memory management suitable for modern high-performance computers, but also a fundamental revision of the kernel code, which removed many limitations and ensured a clearer structure. The developers have been drawing on the clean-up work in the kernel code to this day: Even completely new functions such as virtualization and scaling that has been improved in every respect, thanks to which Linux also runs on the most powerful supercomputers, could be implemented without major distortions.

With Linux 2.6, Torvalds changed the development model: there is no longer a developer kernel, new features and improvements are gradually being incorporated into updates of the current kernel, which appear regularly every two to three months. In the place of version leaps, which repeatedly led to confusion in the conversion phase, steady progress has taken place.

In 2005, Xen, the first virtualization solution for Linux, caused quite a stir in the Linux world; but it would take another six years before the Xen code was fully integrated into the kernel. In the meantime, the alternative solution, KVM (kernel-based virtual machines), which turns the Linux kernel itself into a hypervisor, has been so well received by kernel developers that it was incorporated into kernel 2.6.20 at the beginning of 2007.

The increasing success of Linux in the server area gave the free system a long, seemingly endless history: the legal dispute between SCO and the Linux world. The history of SCO is somewhat bizarre: The provider of a commercial Unix version for x86 PCs was taken over by the Linux distributor Caldera in 2000 - Linux had already started to nibble on the market share of the expensive commercial Unixes before the turn of the millennium, and SCO's Unix business went from bad to worse.

SCO vs. Linux

The combination of an established Unix provider with a well-developed sales structure and an experienced Linux distributor seemed to offer all the prerequisites for opening up the market for Linux in companies. But Caldera fell more and more behind competitors such as Red Hat, who consistently rely on Linux and open source. Two years after the takeover, Caldera changed its name to SCO Group, and six months later the company switched from Linux to litigation.

In spring 2003, the SCO Group sued IBM for $ 1 billion in damages. IBM pushed Linux and not only stole intellectual property from SCO, but also nurtured the free operating system into serious Unix competition, so the main points of the lawsuit. This was followed by threats, alleged evidence, delays due to more and more new applications in court as well as lawsuits against Linux users and the distributors Red Hat and Novell - the latter for the copyright to Unix, which both Novell and SCO claim for themselves and which is the basis of all other SCO lawsuits. Last year the court awarded Novell the Unix copyright, and it seems that the long bankrupt SCO Group is now at an end. But it wouldn't be the first time in long history that appearances are deceptive ...

For Microsoft, SCO's legal campaign against Linux turned out to be a great starting point. Initially, arguments such as the allegedly easier administration and lower Total Cost of Ownership (TCO) of Windows replaced the blanket defamation of Linux and open source as the devil's stuff. From 2004 Microsoft took advantage of the legal uncertainty that the SCO lawsuits were spreading and put on the "higher legal certainty" card. The suggestion that Linux infringed Microsoft patents brought so much uncertainty into the market that IBM, NEC, Novell, Philipps, Sony and Red Hat founded the Open Invention Network in 2005 to defend against patent attacks on Linux. Although until today no court has decided whether Linux actually infringes Microsoft patents, today providers of Android smartphones, for example, transfer license fees to Redmond. But in the smartphone market there is currently more competition via patents, copyrights, lawsuits and competitive complaints than via technology.

In 2006 Microsoft also accepted the importance of Linux in the IT market: a cooperation with Novell made the company itself a Linux distributor, which offers its customers the Suse Linux Enterprise Server with great success. Microsoft has been one of the companies that have jointly developed the Linux kernel since 2009 - and recently even congratulated them on their twentieth birthday with a video.

Since 2007, the Linux Foundation, which emerged from the merger of the Open Source Development Labs (OSDL) and the Free Standards Groups, has been working to strengthen Linux's competitive position. The foundation, whose members include almost all companies that have anything to do with Linux, guards the Linux Standard Base, pays central developers such as Linus Torvalds and looks after the protection of the Linux brand. The Linux Foundation ultimately offers a neutral platform on which companies that are competing in the market can work together - similar to what they do with kernel development.

The long way to world domination

The current kernel 3.0, released a few weeks ago, follows the tradition of continuous progress introduced with Linux 2.6: It differs from its predecessor - Linux 2.6.39 - no more than any two successive 2.6.x versions. Linux 3.0 is just another name for the upcoming 2.6.40 kernel. The biggest change in Linux 3.0 is the new, two-digit numbering scheme: The 3.0 kernel will be followed by version 3.1.

And what about the world domination that Linus Torvalds spoke of many years ago, when Linux was still an exotic hacking project? Where Torvalds was most likely to expect success - on (desktop) PCs - Linux is still a niche solution. In the data centers it looks different: Here the free operating system has long been on an equal footing with Windows and the commercial Unix variants. Linux clearly dominates high-performance computing, and even on the Internet - from Google to eBay to Facebook - and in the cloud, there is no getting around the former PC Unix. With Android, Linux is well positioned in the booming smartphone and tablet business.

Linux popularized the idea that all interested parties should develop software together in an open process - and proved that this can not only work in such a huge project as the Linux kernel, but also offers tangible advantages. The boom that open source software has experienced since the turn of the millennium is likely to be largely due to the success of the free operating system.

Thanks to its flexibility, Linux will also be able to adapt to new developments that are likely to further change the IT world in the next few years. Or, as Red Hat boss Jim Whitehurst put it at LinuxCon on the occasion of its twentieth birthday: "The power [of Linux] lies in what people can do with it". In this sense: for the next twenty years. (odi)