Common Public License
From Wikipedia, the free encyclopedia
The CPL (Common Public License) is a free software / open-source software license published by IBM. Its license terms have been approved by the Open Source Initiative and Free Software Foundation. The CPL's stated aims are to support and encourage 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) is a slightly modified version of the CPL.
The CPL has some terms that are similar to the GNU General Public License, but there are some key differences. A key difference is relicensing: one may compile a Program licensed under the CPL without modification and license it under a proprietary license. Another key difference is in a patent clause designed to prevent unscrupulous contributors from contributing code which infringes on their patents, and then attempting to charge royalties; in such a situation, the CPL requires the contributor to grant a royalty-free license to all recipients. This additional requirement renders the CPL incompatible with the GPL (in the opinion of Eben Moglen, and the GNU website), though it is possible that a future version of the GPL will adopt a similar, compatible clause. A similarity is related to a distribution of a modified program: under either license (CPL or GPL), one is obligated to make the source code to the modified Program available to others.
Microsoft has released their Windows Installer XML (WiX) developer tool, Windows Template Library (WTL) and the FlexWiki engine under the CPL as Sourceforge projects.
