Definition: Open source
The fundamental principle of the Open Source Licensing is that it prohibits anyone from exclusively exploiting a given piece of work. In order to reflect this, a legal framework was originally developed to guarantee the openness by a certain set of principles. The principles as defined by the Free Software Foundation : The freedom to run the program, for any purpose (freedom 0) The freedom to study how the program works, and adapt it to your needs (freedom 1) Access to the source code is a precondition for this The freedom to redistribute copies so you can help your neighbour (freedom 2) The freedom to improve the program and release your improvements to the public, so that the whole community benefits (freedom 3). Access to the source code is a precondition for this.
Semantic Operability Centre Europe (SEMIC), Initiative by Director-General "Informatics" of the European Commission, Online glossary