Welcome to the second episode of Asterisk Myth Busters. In this installment, we’ll investigate a common misconception regarding the Asterisk contributors’ license agreement.
MYTH: Digium requires code contributors to give away their rights.
Contributors to any open source, GPL-licensed project willingly grant specific rights, while maintaining copyright on their contribution. Digium, as the sponsor of the Asterisk, has required from the inception of the project that contributors to Asterisk sign the contributors’ license agreement – a policy that is designed to ensure that Asterisk remains free of legal encumbrances. The purpose of this agreement is to clearly define the terms under which intellectual property has been contributed and thereby allow us to defend the project should there be a legal dispute regarding the software at some future time. While the Asterisk contributor’s license agreement does enable commercial licensing, all code contributed under this license agreement is available freely under the GPL. Digium’s commercial license revenues directly fund continued open source development. This is truly a dual licensing model, in which the use of one license does not diminish the other.
While there are those that take exception to this policy, there are precedents among other very successful open source projects that are in line with the Digium policy. For example, the Apache Software Foundation requires a signed Contributor License Agreement to be on file before an individual is given commit rights to an ASF project ( http://www.apache.org/licenses/icla.txt ). There are also precedents with more strident legal requirements such as the Free Software Foundation’s policy which requires copyright assignment or disclaimer to accept GNU contributions ( http://www.gnu.org/prep/maintain/maintain.html#Legal-Matters ). Digium is not blazing a new trail here, just working to apply best practices to the Asterisk project.
OUTCOME: Busted. Contributors keep their copyrights