Common Public License
||This article should be divided into sections by topic, to make it more accessible. (January 2013)|
|DFSG compatible||Yes |
|Linking from code with a different license||Yes|
In computing, the CPL (Common Public License) is a free software / open-source software license published by IBM. The Free Software Foundation and Open Source Initiative have approved the license terms of the CPL.
The CPL has the stated aims of supporting and encouraging collaborative open-source development while still retaining the ability to use the CPL'd content with software licensed under other licenses, including many proprietary licenses. The Eclipse Public License (EPL) consists of a slightly modified version of the CPL.
The CPL has some terms that resemble those of the GNU General Public License (GPL), but some key differences exist. A similarity relates to distribution of a modified computer program: under either license (CPL or GPL), one must make the source code of a modified program available to others.
CPL, like the GNU Lesser General Public License, allows non-CPL-licensed software to link to a library under CPL without requiring the linked source code to be made available to the licensee.
CPL lacks compatibility with both versions of the GPL because it has a "choice of law" section in section 7, which restricts legal disputes to a certain court. Another source of incompatibility is the different copyleft requirements.
IBM, along with several people from academia, started CPL licensed COIN-OR projects to provide free and open-source software relating to optimization and operational analysis. The initiative led to establishment of the COIN-OR Foundation.
To reduce the number of open source licenses, IBM and Eclipse Foundation agreed upon using solely the Eclipse Public License in the future. Open Source Initiative therefore lists the Common Public License as deprecated and superseded by EPL.