Open source software is characterised on the one hand by the fact that the source code is published and thus accessible to everyone, and on the other hand by the fact that it can usually be used free of charge.
One of the first and best known examples is the former browser Netscape. Its source code was released in 1998, as it was no longer economically viable at the time due to the overwhelming dominance of Microsoft in the browser market. This later developed into the Mozilla project. Even better known and more important is Linux, which was created in the 1990s by Linus Torvalds as a freely available operating system.
The Open Source Initiative (OSI) was founded because of the consideration that such free software needed better marketing in order to present it to the outside world as business- and user-friendly and free from ethical values or categories. At the same time, appropriate licenses were created to meet the needs of the environment and to make the topic appealing to commercial users.
The definition of Open Source according to OSI
Software that wants to adorn itself with the Open Source label must essentially meet three criteria.
- the source code is available in a form that can be read by humans, i.e. in a higher programming language and not in a compiled binary code with which the computer finally does its work
- the software is freely available and may be used, copied and distributed by any user as often as desired. So there are no restrictions regarding the number of users or the number of installations on different computers or payment obligations to a licensor as with normal commercial software.
- the software may be changed, adapted and passed on in this edited version by each user. This point not only includes a lot of freedom for programmers. It is almost the prerequisite for Open Source, because only with their active and unpaid work the development of Open Source is possible.
The economic importance of Open Source
Open source software is not only used by private individuals, but also by companies, authorities, organisations and even governments. A large part of it is Linux as a server operating system used worldwide, the MySQL management system for databases, the Firefox browser and the Thunderbird e-mail program from the Mozilla Foundation. But there are also powerful office suites, graphics and layout software and many other programs that can stand comparison with market-leading commercial applications. The market value of all open source projects worldwide meanwhile amounts to many billions of Euros, whereby an exact number can hardly be determined.