contributorlicense

A contributor license, commonly called a contributor license agreement (CLA), is a legal document used by software and content projects to define the terms under which third parties submit contributions. It specifies how copyrights, patents, and other rights in contributed material are handled so project maintainers can distribute, relicense, or enforce the work as needed.

CLAs typically require contributors to grant a license or assign copyright to the project, make representations about ownership and originality, and grant patent rights or non-assertion covenants. They may be individual or corporate, and can be structured as copyright assignment, exclusive or non-exclusive license, or a simple permission to use and sublicense. Common clauses address warranties, indemnity, confidentiality, and governing law.

The principal purpose of CLAs is legal clarity and risk management: they help projects ensure they have the necessary rights to combine, modify, and redistribute contributed material and to defend against intellectual property claims. Many large open source foundations and corporations use CLAs to facilitate collaboration and downstream licensing decisions.

CLAs are sometimes controversial. Critics argue that copyright assignment or broad licensing can centralize control or deter contributors; supporters emphasize legal certainty for projects and downstream users. Alternatives and complements include the Developer Certificate of Origin (DCO), contributor license headers, and project-specific contribution policies. Projects choose approaches based on legal, community, and governance priorities.