GNU General Public License version 2
From GPLv3 Wiki
The new version of the GNU General Public License will be incompatible with the old version. This seems ironic, but it is the expected and necessary result of a major revision to the license. If there were no qualititative changes needed, then there would be no need for a revision.
The changes to the license come in two flavors. Some changes are clarifications of legal character that do not change either the scope and therefore the comptability of the license. As the GPLv2 said, "Such new versions will be similar in spirit to the present version". Other changes add new requirements to better protect the software's freedom. As the GPLv2 continues, "differ in detail to address new problems or concerns". The rationale for the first draft of the GPLV3 described:
- In a few parts of the revised license, we have reacted to alarming developments by adding certain new requirements, as in our section on DRM. These requirements are narrowly drawn and are directed at preventing the mechanism of freedom from being turned against itself.[1]
Works under the GPLv2 are only compatible with the GPLv3 if they are upgraded manually by the copyright holder(s), or if the work was originally licensed in the manner section 9 of the GPLv2 described:
- If the Program specifies a version number of this License which applies to it and "any later version", you have the option of following the terms and conditions either of that version or of any later version published by the Free Software Foundation.
Back to Compatible licenses.
