open and closed systems

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A "system" is a loose term for a bunch of things that work together, which is usually used with man-made parts rather than people or places. A complete computer includes many complex collections of components. Each collection of components makes up one system. The whole computer makes up one system, built from all these smaller subsystems.

A closed system is owned by one organization and protected so the organization can make money from its use. An open system is developed by a community and is free for use by anyone. Both hardware and software can be included in a system. Hardware systems are almost always closed and software systems, such as an OS and an application that uses it, may be open or closed.

An open system can only work by being built according to open standards. A standard is a description of what a thing is or how it should work. Open standards are available for anyone to read. Many thousands of open standards describe the computer world.

Systems and standards are protected from abuse by free, open source and proprietary licensing.

what it is

A system is a bunch of little things that work together to make one big thing. A human body is a collection of living organs and other sticky bits and pieces. A computer OS (Operating System) is a collection of software. Our solar system is a collection of planets, moons and a sun.

A standard is a description of a widely used way of working. A dictionary gives a standard definition for each word. House doors are supplied in standard widths. A civil law describes something a person is allowed to do in a community. There are huge amounts of computer industry standards.

Anyone is free to create a description of how systems should fit together and give it to anyone who will take it. Any organisation is free to build systems that follow this description. The description does not really become a standard until many organisations start to use it.

a computer system

Any computer that can actually do anything is choc full of systems. Computers are the most complicated things people have ever made. Every piece of hardware and software is a system, such as a NIC (Network Interface Card), a database application and a keyboard.

Complicated systems means expensive systems, which means every business making computer systems needs to make a lot of money to justify spending truckloads of money on research and development. There are two main approaches to dealing with this expense: making closed systems and making open systems. A closed system is proprietary (owned exclusively by one company). A closed system needs to be protected: the owner must stop others from using it. An open system is free for use by anyone. It must comply to a set of open standards and work well with other open systems.

The little things in a system may able to work independantly or they may rely on each other to function. Take a kidney out of a human body and it soon stops being a kidney. A business enterprise is also a bunch of little things that work together to make one big thing, but take the people out of that kind of system and they don't keel over and die.

a closed system

A computer company that builds complete systems, such as writing its own applications, can make money from closed systems. A closed system is one where nothing gets in or out. There are several ways of stopping things getting in or out.

  • technical barriers. A computer company can make computer systems that do not work with any other company's systems. The customer has to continue using the company's own products.
  • legal barriers. A company can patent and copyright their systems. They can then rent it out to others and make money from royalties. The company can also sue the ass off any other company that copies their systems.

A closed system is created by a development team. The people in the team work for a business enterprise. The work they do is valuable to other businesses so they are told to keep their work secret: they cannot share their work with others.

an open system

An open system exchanges things with other open systems. An open system follows open standards that guarantee it can talk to other systems.

An open system is also open in its construction: anyone can examine the way it works by reading the computer programs that it is composed of.

An open system is created in the same way that a closed system is created, with one big difference. The development team do not keep the work secret: it is shared with any person who wants it. Some of these people are allowed to collaborate with the team to help create the system.

Sharing and collaboration are attractive ideas to Internet hackers. Open systems such as Linux and other free software have become the pagan gods of the hacker culture.

A computer company that does not build complete systems, such as one that sells services, can make money from open systems. The expense is shared between many companies because they all contribute to creating one system. These companies can't make much money from selling the system because they don't own it but they can make money selling their expertise.

an open standard

An open standard is a description of how things should be done in the computer world. Some standards describe protocols that lets two different applications talk to each other (a big word for this is called interoperability). A standard may also describe a computer language, design principles or

Every open standard is based on the same set of principles and practices which prevent things like discrimination, ownership and paying royalties. There are no legal barriers that stop anyone using open standards, but there are legal barriers that prevent companies from damaging open standards.

Open standards are produced and maintained by non-profit organizations. These are usually international consortiums whose members come from businesses and universities. The paragraphs below describe three famous organizations. The IETF (Internet Engineering Task Force) looks after Internet standards, the W3C (World Wide Web Consortium) looks after WWW standards and OASIS (Organization for the Advancement of Structured Information Standards) looks after e-commerce standards.

Open systems can only work if they conform to open standards. A company helping to build an open system has to use open standards. A company building a closed system may also use some open standards if their customers want it.

The Internet is described by thousands of standards. A system cannot use Internet resources without following open standards. New ideas for Internet standards are created by smart people who write Internet-Drafts and send them to a committee called the IETF (Internet Engineering Task Force). Guys called RFC-Editors publish them as RFCs (Requests For Comments) with interesting names like RFC1, RFC2 and RFC4400. The popular ideas are eventually ratified as standards.

The WWW (World Wide Web) is an application that runs on top of the Internet. The WWW also described by standards. A committee called W3C (World Wide Web Consortium) published about 90 standards describing the web, including HTTP (Hyper Text Transfer Protocol), HTML (Hyper Text Markup Language) and XML (eXtensible Markup Language).

There are standards for e-commerce. A consortium called OASIS (Organization for the Advancement of Structured Information Standards) maintains dozens of standards that describe how e-commerce can work over the Internet, such as UBL (Universal Business Language) and ebXML (Electronic Business using eXtensible Markup Language)

what it isn't

God's gift to solve the world's problems. The appeal of open systems attracts single minded individuals who may preach against closed system suppliers.

An open standard is not a required standard. Participation is voluntary.

where it is

Every part of the LIC contains open systems, from the PCI bus in each computer to the OS and the customer applications.


From the start of the computer industry to the 1990s you got what you were given. There was no choice because there was no interoperability. Each computer company was guaranteed repeat business because customers were locked into the company's products.

From the late 1980s open standards caught on because they were attractive to open source programmers. If you find open standards attractive then you are a true nerd.