Debian Free Software Guidelines - The Guidelines

The Guidelines

  1. Free redistribution.
  2. Inclusion of source code.
  3. Allowing for modifications and derived works.
  4. Integrity of the author's source code (as a compromise).
  5. No discrimination against persons or groups.
  6. No discrimination against fields of endeavor, like commercial use.
  7. The license needs to apply to all to whom the program is redistributed.
  8. License must not be specific to Debian, basically a reiteration of the previous point.
  9. License must not contaminate other software.
  10. The GPL, BSD, and Artistic licenses are examples of licenses considered free.

Read more about this topic:  Debian Free Software Guidelines