FAQ: Common Development and Distribution License (CDDL)
What is the CDDL and why was it chosen for the Open Media Commons initiative? CDDL is the Common Development and Distribution License. It is an open source license that takes the well-known Mozilla Public License (MPL) and makes it reusable without modification. We wanted a copyleft license that provided the protections and freedoms necessary for true open source, as well as enabling creation of larger works for commercial purposes. Has the CDDL been approved by the OSI? Yes, the CDDL meets the requirements of the Open Source Definition and has been approved as an open source license by the Open Source Initiative. Why did you write another open source license? When we decided to open source OpenSolaris, we reviewed a number of existing open source licenses, but were unable to find one that that was appropriate. Therefore, we reluctantly drafted a new license, with the goal of creating a license that was clear, consistent, not burdensome for contributors, and as reusable and general as possible (the same issues we are concerned about for Open Media Commons). We do appreciate the problem of license proliferation, however, and have designed the CDDL to be reusable and attractive to other open source projects with similar goals. We hope this will help reduce the proliferation of open source licenses by reducing the need for customized versions of the MPL. We believe that this license is the most appropriate for Open Media Commons as well. Will all of the Open Media Commons projects be released under the CDDL? We plan to release as much of the source code as possible under the CDDL. Why did you base the CDDL on the MPL? The MPL is a well-regarded license and had several attributes Sun was looking for, including:
What improvements over the MPL did you make? In addition to retaining all desired features of the MPL (detailed above), the CDDL is designed to be reused by others and contains several improvements to make it more general:
See also a summary description of the changes and the redline diffs (PDF) between the MPL 1.1 and the CDDL. If you wanted a copyleft license, why didn't you just use the GPL or LGPL? We needed an open source license that allowed files released under the license to be linked with files released under other licenses. While a license like LGPL would allow this for dynamically linked code, we also needed to be able to release software that statically links source files available under different licenses. In addition, we wanted to allow others to add extensions to Open Media Commons projects with different license terms. This was only possible under a license like the MPL; however, we could not use the MPL because it is not a "template" license allowing reuse by others. Consequently we crafted a new variant of the MPL, taking the opportunity to make it a template license as a step towards reducing license proliferation for others finding themselves in the same position as us. What does the CDDL say about patents? The CDDL provides an explicit patent license for code released under the license. This means that you can use, modify, and redistribute code released under CDDL without worrying about any patents that the contributors of the code (including Sun) might have on the contributed technology. The license also includes a provision to discourage patent litigation against developers, by revoking the rights to the code for anyone initiating a patent claim against a developer regarding code they have contributed. Can code licensed under the CDDL be combined with code licensed under other open source licenses? CDDL is file-based; that means that files licensed under the CDDL can be combined with files licensed under other licenses, whether open source or proprietary. However, other licenses may have different restrictions which may prevent such combination; be sure to read and recognize those. What about dual licensing? Can I license my code under the CDDL as well as another license? Yes, if you are the copyright owner for the code you can choose to license under multiple licenses, including the CDDL. Yes, for any source files that are licensed under the CDDL and any modifications you make. However, you don't need to share the source for your proprietary source files. Code contributed to the Open Media Commons projects source base must be made available under the CDDL (or another open source license if based on another open source project with a different license), and you must have submitted a contributor agreement. We're working out the details of the code submission process. May I take portions of the Open Media Commons projects source code and use it in another code base?Yes, you can use the Open Media Commons projects source code in other projects as long as you comply with the terms of the CDDL. Can I redistribute or sell the Open Media Commons projects source code with my modifications? Yes, you can modify and redistribute code licensed under the CDDL, including charging for it if you wish. However, you will need to meet the terms of the CDDL, including making the source of your modified code available under the CDDL. May I use the Open Media Commons projects source code or binaries commercially? Yes, you may use the Open Media Commons proejcts source code in commercial products. Note that if you distribute binaries built from code released under the CDDL, you will need to meet the terms of the CDDL and distribute the corresponding source code under the CDDL. See the license for details. Can I use the CDDL for my project (unrelated to the Open Media Commons program)? Yes, the license is intended to be reusable for other projects, including projects from parties other than Sun. Can Sun ever take away the Open Media Commons projects source code? No. The code is available to the community forever. |
