The market share of Linux is 100%

The reason why Linux has become the only operating system for modern computing is located within the computing history. We have to go back in the early 1980s. In that time, universites and cooperations have bought the newly introduced DEC VAX minicomputer. A typical device was sold for 300000 US$ and provided only 1 MB of RAM. Later generation of the VAX series was called Microvax, VAX cluster and in the early 1990s all the hardware power was put into a workstation like desktop. What remains the same from the 1980s until today is the operating system. The first VAX machines were driven by a Unix operating system and a modern developer PC runs with Linux.

The reason why in the 1980s the VAX computer was equipped with Unix, the later Microvax machine in the late 1980s with BSD, the first Workstations with SunOS and a modern PC with Linux is because without an operating system a computer wouldn't work. Before somebody can install opplications, surf in the internet, and use external discstorage some kind of master control program has to be started first. The kernel gets access to the hardware and on top the kernel user applications can be startet. This master control program is equal to the operating system which is Linux.

The funny thing is, that in 1980s, 90s, 00s and 10s no one has compared Unix with a potential alternative. The situation is, that if somebody decides against Unix/Linux he has no operating system at all. There is no alternative minicomputer operating system for driving larger computers or for powering a developer workstation.

Microsoft has developed a software called Windows NT which can drive a server too. The problem with NT and Microsoft server is, that the system wasn't designed for larger computers in mind. It is not able to power a VAX cluster, and doesn't provide programming tools for example a C-Compiler. The only purpose why Windows NT and Windows Server is sold to the enduser is convince them to buy addtional software which runs also under Windows. That means, Windows is not an operating system from a technical sense, but a marketing tool which puts the customer into a sandbox and restricts his interaction with the computer. For homeusers who want to install the latest GTAV game this might be an interesting option, but for universities who want to educate students in writing software and analyze databases this makes no sense. That's the reason, why Windows NT never was a scuccess in the datacenter. It is equal to Amiga OS a firmware which runs on a certain computer type and is maintained by single company. If the Intel x86 architecture or Microsoft becomes obsolete, the Windows software will decline.

The main reason why datacenters have a need for an operating system is because they are customers from different hardware companies. They have bought the minicomputer from DEC, the printer from HP, the harddrive from seagate and the file storage cluster from compaq. Using a firmware from one of these suply company won't work because the idea to connect all these devices together. This task is handled by a vendor independent operating system. This system is standardized (POSIX) and provides hardware driver for all the equipment. Additional the operating system is the platform for the user. The first user likes to run a webserver, the second likes to program in Java and the next one writes a Python script. The operating system has to handle all these task with the same priorioty. It's not up to the operating system to explain to the user, that Python is bad programming language and he should switch to Borland Pascal. No, the idea is to do what ever the user wants.

Why was the DEC VAX11-780 successful?

In most cases a look back to the history of Digital Equipment Corporation comes to the conclusion that since the 1990s the company has made everything wrong and as a consequence DEC has declined. And indeed, DEC wasn't able to survive the upraising of the x86 computer and the former workstation and server products were integrated in today's HP company.

The more interesting question is why was in the 1980s DEC the number one in computing? They have made something right and sold their products to many satisfied customers. To understand the history we have to describe the divided market of computers in that period. On the low range, there was the upraising of homecomputers, for example Apple II, 286'er IBM PC, Commodore 64 and the Atari 2600 gaming console. In the midrange was DEC, and early Workstation vendors like Sun, and in the market for mainframe computers there was IBM.

The most interesting question is, why DECs customers have bought Unix based superminicomputers and not Amiga 500 and IBM PCs. Why was a VAX11-780 superior over a Commodore 64 computer? The purpose of the computers was different. Homecomputers were designed for playback existing software. The typical example was the Atari 2600 system which was able to run a ROM image which was sold separate. While DEC VAX computers were designed to create software and create CAD drawings. That means, the computer market was divided into entertainment where the software was delivered as ROM image created by publishing houses, and in contrast the DEC computers were sold to professional users who were programmers.

This distinction helps to compare the different software which were installed on the machines. Homecomputers like the Commodore 64 were equipped with a ROM kernel. Their main purpose was to provide a plattform which was able to playback existing games and applications. In contrast, Unix minicomputers and in the late 1980s also Unix workstations were designed as a programmer friendly environment which provided a shell, a compiler and a GUI interface.

The reason why professional customers and universities have bought the VAX computer was the need to use a computer as a programming device. The typical VAX user was interested in programming a scientific application in the C language, write a documentation with the troff formatting tool and send the project as E-Mail to a different university. The VAX computer was perfect for this task. And here comes the interesting point. Digital Equipment Corporation has become obsolete, the VAX hardware is useless for today's applications but the requirement of programming something in C, format a manual with a formatting language and communicate with other researchers are remain the same. This explains why today's homecomputers can be ignored by programmers. Apple, Microsoft or Nintendo have nothing to offer what is relevant for developers. The Nintendo Switch gaming console was designed well but it's the wrong choice, if somebody likes to learn Python programming. And the Microsoft 10 operating system is a wonderful platform for playback AAA game titles, but it is useless, if somebody likes to install a webserver.

Today's Linux is what DEC was in the 1980s: the number one platform for developers. It is equal to a fully functional operating system which includes multitasking and network capabilities and is used by 100% of all developers for realizing their projects.

Timeline of computing

Sometimes, a modern PC is presented as an extension of older PC which were build in the 1980s. But in a computer lab the transitation was different. In a computerlab, today's PC followed the former SUN workstation and the SUN systems has replaced the VAX11-780 system. That means, the processing speed and the operating system is constant over the last 40 years but the price has dropped and the size of the machine has become smaller.

Installing WIndows 10 on a PC of a computer lab is similar to installing MS-DOS on a DEC VAX machine. It makes no sense, because it doesn't fulfill the needs of the users. A computing lab has the obligation to teach students programming in C, not to teach them to buy software from the Microsoft store written by other.

The VAX11-780 computer

In the late 1970s a revolutionary computer was introduced the DEC VAX11-780. In contrast to the Apple II it was an expensive computer which targets programmers. A typical VAX11-780 had around 1 megabyte of RAM and a moderate CPU for doing the calculations. The more interesting point of the machine was the software. It was an early UNIX version installed on the VAX machine, very similar to what today's programmers are using. Or to explain it from the other perspective: the operating system never changed in the last 40 years. Only some details were improved.

To understand why the VAX computer in the late 1970s was relevant for the programmers we have to look at some details of the UNIX operating system. Mainly it provided a textbased terminal (similar to a bash), the troff document formatter (similar to today's LaTeX), it was equipped with a C compiler, it had network capabilities (DECnet), it was possible to run many programs simultaniously, it contains a texteditor and last but not least a version control system called SCCS.

Which part of the software stack has become obsolete for today's programmers? Right, nothing of them. The tools were improved only in details but the general today is the same like in the late 1970s. The combination of all the unix tools together results into a powerful machine. The programmer can enter with the texteditor C sourcecode, compile it into binary format, document the program with a markup language, writes an e-mail to other programmers over the Internet and while he is doing so a different user can execute on the same machine different programs in the background. This efficient pipeline is using the existing ressources optimal and even from today's perspective it's hard to find something which should be improved.

What makes the VAX11-780 computer unique is, that it was the first time that a reasonable powerful hardware with around 1 MB was combined with a UNIX operating system. This allowed programmers to create software projects. It was the beginning of new area which is active since today.

Sure, DEC was not the only computer company in the 1970s, and The C programming language was not only way to program a computer. But all the other companies like IBM, Apple or Atari were amateurs. They have produced software and hardware but it was different from Unix.

The funny thing is, that in 1970s it was not obvious, that DEC VAX-11/780 was a powerful machine. The IBM mainframe system were from a technical side faster, which means, they had more RAM and the CPU was more powerful. While companies like Tandy Corporation or Apple computers sold more units to a mass market. What DEC has provided to the world was a programming environment. This idea was more powerful than IBM hardware and Apple's mass market combined.

What exactly was this ideology? Mainly it has to do with the UNIX operating system, not because of the tradename Unix but because of the idea of an operating system. Let us define from an abstract point of view what an operating system is. It's a system software which provides a compiler, debugging tools, version control, networking capabilities, and a command interface for multiple users. For running such an operating system a hardware with at least 1 MB of RAM is needed. DEC Was a company who provided this combination for the first time.

The ideology was not connected to DEC, but the ideology says basically that there is a need for an operating system which runs on a computer. This is equal to a programmer environment which allows users to create software. The funny thing is, that other companies didn't focussed on this point. For example, IBM had never programmed an operating system. IBM had equipped their mainframe system with customized firmware, but not with a software which runs on different hardware. In contrast, a company like Apple was interested in selling hardware to the customer. He became a gaming console which allows him to start software written by other. Only DEC assumed, that the customer want's to create his own software so he needs an operating system.

What DEC has invented with the VAX-11/780 was not only a hardware/software combination, but a learning space for future programmers. Suppose, a university had bought the VAX computer, what will happen next? Right, the students are encouraged to write software in C for the machine. They are doing so in computer courses and as a result they learn programming. I would call DEC not a computer company, but a computer course. The idea is to increase the number of students who are fluent in the c language and have experience with networked timesharing computers.

From a negative perspective, the DEC VAX computer was a waste of time. The students have learned how to program a game, and if they have done so they played with the machine. They never produced useful software but used the machine as a toy to satisfy their own needs. The DEC machine can be compared with today's Lego Mindstorms Kit. The only purpose of the NXT2.0 brick is to educate the student who to solve problems. It is an education tool for making human smarter.