Free and Open Source

Open Source software is Free Software, and Free software is Open Source software.

Different approaches:

• Free refers to what is essential, freedom.
• Open Source is more about the quality of software developed in an open and decentralized manner. Pragamatic marketing.

( This does not mean that the Free software movement, which promotes copyleft, is not pragmatic. )

The OSI's definition of Open Source in one paragraph is similar to the definition of Free software of the FSF:

Open source promotes software reliability and quality by supporting independent peer review and rapid evolution of source code. To be OSI certified, the software must be distributed under a license that guarantees the right to read, redistribute, modify, and use the software freely.