This document discusses open source software licenses and how they provide users certain freedoms like using, studying, sharing, and improving code as long as others are granted the same freedoms. It outlines licenses like the GNU GPL, BSD, and Apache licenses, explaining how copyleft ensures freedoms are maintained in derived works. It notes that people should read and follow license terms to avoid issues, and that long-term maintenance benefits from assignment to reduce fragmentation. Contact details are provided for the Freedom Task Force which provides training and consultancy on legal infrastructure regarding open source licenses.

1. Licences that support freedom

2. Four Freedoms
Use
Study
Share
Improve

3. Provided by licences
What users can do
What subsequent users can do

4. The important thing
Understand the reasoning
behind the licence

5. The GNU GPL
You can use, study, share and improve this
code as long as others now and in the
future also have these freedoms.
(the legal text is longer)

6. Examples of licences
Modified BSD
GNU LGPL
GNU GPL
Apache
MPL
Affero GPL

7. Copyleft
Freedom maintained in modified or
improved versions of the software

9. Common issues
People don't read the licences
People don't follow the licence terms

10. Avoiding issues
Read the licences
Follow the licence terms

11. Long-term maintenance
Assignment can reduce fragmentation

12. Freedom Task Force
Training
Consultancy
Legal infrastructure

13. Contact details
ftf@fsfeurope.org
www.fsfeurope.org/ftf

14. This presentation is released under the
terms of the Creative Commons Attribution-
Sharealike 3.0 licence.
http://creativecommons.org/licenses/by-sa/3.0/