The Free Software Definition

The canonical source for the document is in the philosophy section of the GNU Project website.

[3] The FSF publishes a list of licences that meet this definition.

Finally, another freedom was added, to explicitly say that users should be able to run the program.

[6][7] The modern definition defines free software by whether or not the recipient has the following four freedoms:[8] Freedoms 1 and 3 require source code to be available because studying and modifying software without its source code is highly impractical.

In July 1997, Bruce Perens published the Debian Free Software Guidelines.