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 differing copyleft requirements.[2]
To reduce the number of open source licenses, IBM and Eclipse Foundation agreed upon using solely the Eclipse Public License in the future.[4] Open Source Initiative therefore lists the Common Public License as deprecated and superseded by EPL.