The Common Public Attribution License ("CPAL") is a free software license approved by the

Open Source Initiative The Open Source Initiative (OSI) is the steward of the Open Source Definition, the set of rules that define open source software. It is a California public-benefit nonprofit corporation,_with_501(c)(3).html" ;"title="110. - 6910./ref> is a type o ...

in 2007. Its purpose is to be a general license for software distributed over a network. It is based on the

Mozilla Public License The Mozilla Public License (MPL) is a free and open-source weak copyleft license for most Mozilla Foundation software such as Firefox and Thunderbird The MPL license is developed and maintained by Mozilla, which seeks to balance the concerns ...

, but it adds an attribution term paraphrased below: The CPAL also adds the following section discussing "network use" which triggers

copyleft Copyleft is the legal technique of granting certain freedoms over copies of copyrighted works with the requirement that the same rights be preserved in derivative works. In this sense, ''freedoms'' refers to the use of the work for any purpose, ...

provisions when running CPAL licensed code on a network service and this way closing the so-called

ASP loophole The Affero General Public License (Affero GPL and informally Affero License) is a free software license. The first version of the Affero General Public License (AGPLv1), was published by Affero, Inc. in March 2002, and based on the GNU General Pu ...

: The

Debian Debian (), also known as Debian GNU/Linux, is a Linux distribution composed of free and open-source software, developed by the community-supported Debian Project, which was established by Ian Murdock on August 16, 1993. The first version of D ...

project found the license to be incompatible with its Free Software Guidelines (DFSG) because of its attribution requirement.

References

External links

{{Portal, Free and open-source software
CPAL version 1.0 text
at the Open Source Initiative *Jonathan Corbet on July 31, 2007 on LWN.net:
Open-source badgeware
, discussing problematic attribution requirements Free and open-source software licenses Copyleft