FSF publish guide on choosing a licence
The Free Software Foundation (FSF) have published "How to choose a license for your own work", a guide to selecting a licence for developers. Brett Smith of the FSF's Licensing Compliance Labs introduced the new document as a consolidation of previously scattered advice from the FSF.
As would be expected, the FSF recommend that software use "the strongest copyleft license", which in general is the most recent version of the GNU General Public Licence (currently GPL version 3) and where appropriate, the GNU Lesser General Public Licence (LGPL) for libraries and the GNU Affero GPL (AGPL) for network accessible applications.
The document does recommend a non-FSF originated licence, specifically for situations where free standards are competing with proprietary standards. In this case the Apache Licence 2.0 is commended because it has language which prevents contributors and distributors from suing for patent infringement. Smith gave credit to the Apache Software Foundation for "pushing to do more to tackle software patents in a license, and implementing an effective strategy in the Apache License". He does point out though that the Apache Licence 2.0 is incompatible with the GPLv2 but "every major copyleft license has or will soon have Apache compatibility in their latest version".
Other licences recommended by the FSF include the GNU Free Documentation Licence (for documentation), CC0 (for code snippets) and Creative Commons Attribution ShareAlike (as a general copyleft for other works).