Free and Open Source software
openSUSE has been developed on the concept of Free and Open Source Software (FOSS), which is software that is liberally licensed to grant the right of users to use, study, change, and improve its design through the availability of its source code.
In the context of free and open source software, free refers to the freedom to copy and re-use the software, rather than to the price of the software. One should "think of free as in free speech, not as in free beer".
"Free and Open Source Software" is an inclusive term which covers both free software and open source software which, despite describing similar development models, have differing cultures and philosophies.
- Free Software focuses on the philosophical freedoms it gives to users while
- Open Source focuses on the perceived strengths of its peer-to-peer development model.
Free software licences and open source licenses are used by many software packages. While the licenses themselves are in most cases the same, the two terms grew out of different philosophies and are often used to signify different distribution methodologies.
GNU Project and Linux kernel
In 1984, Richard Stallman initiated the free software, mass collaboration GNU Project that began developing the GNU operating system in 1984, "GNU" being a recursive acronym that stands for "GNU's Not Unix".
The founding goal of the project was to develop "a sufficient body of free software to get along without any software that is not free." The project initially made good progress, and by the early 1990s, the only major component missing was the kernel - the low level core of the system that needs to interact with the hardware.
The complete operating system is a so called Linux distribution (also called GNU/Linux distribution by some vendors and users) typically built on top of the Linux kernel, tools and utilities from the GNU project, and includes graphics support with the X Window System, a large collection of software applications and plenty of documentation.
Hence, a Linux distribution is not a monolithic operating system simply called "Linux", but rather a combination of many more or less independently developed "upstream" projects. This modularity is what allows for a wide variety of Linux distributions, and it is due to the Free and Open Source Software concepts allowing anyone to modify, bundle and redistribute the software that it is legally and practically possible for the Linux distributors to make distributions.