At the beginning of the month, OceanBase, a self-developed database product developed by Ant Financial , announced that it is open source and adopts the Mulan public agreement MulanPubL-2.0. Some articles refer to this agreement as the "Mulan License".
In fact, such abbreviations are prone to confusion. The Mulan series of licenses include the "Mulan Permissive License" and the "Mulan Public License", both of which are led by Peking University, relying on the National Beacon Commission Cloud Computing Standards Working Group and the China Open Source Cloud Alliance, and combine the advantages of the industry, academia and research in the open source ecosystem. Teams and individuals, especially open source lawyers and lawyers, draft, revise, and publish.
Zhou Minghui, a professor at Peking University, the initiator of the Mulan series license, said that both the loose version and the public version use the preposition of Mulan, hoping that Mulan will form a system and ecology, and prosper together. Replacing one of them can easily cause confusion.
In the Mulan series of licenses, the Mulan Permissive License Version 2 ( Mulan PSL2 ) has been approved by the Open Source Promotion Association OSI on February 14, 2020, becoming the first open source license with international generality in China. Currently the most well-known license of the Mulan series. Therefore, the term "Mulan License/Agreement" is often used to refer to the Mulan Permissive License Version 2, but this reference is also inaccurate.
| license |
English abbreviation |
release time |
| Mulan Permissive License Version 1 |
MulanPSL |
August 2019 |
| Mulan Permissive License Version 2 |
MulanPSL2 |
January 2020 |
| Mulan Public License Version 1 |
MulanPubL-1.0 |
December 2020 |
| Magnolia Public License Version 2 |
MulanPubL-2.0 |
May 2021 |
There is a big difference between the Mulan Permissive License and the Mulan Public License. Taking version 2 as an example, the difference between the Mulan Permissive License and the Mulan Public License focuses on "distribution restrictions".
The Mulan Public License, like the GPL, is contagious and requires recipients to open source code. The "distribution restrictions" of Mulan's relaxed license only requires the license statement in the code to be retained, and does not require the license settings when redistributing, and does not have the "contagious" feature.
The figure below shows a detailed comparison of the "distribution restrictions" of the two versions of the license. The public version is more accurate in the representation of the constraints (highlighted in blue).
[Software] in the permissive license and [ "contributions you receive or your "derivative works" ] in the public license can be understood to describe the same object. Zhou Minghui said that due to the late formulation of the public license and the differences in the context of the two versions, a more precise and well-understood description was used in the formulation of the public version.
| license |
Mulan Permissive License Version 2 |
Magnolia Public License Version 2 |
| distribution restrictions |
You may redistribute the Software in source or executable form, with or without modification, in any medium, provided that you provide recipients with a copy of this License and retain copyright in the Software, Trademarks, Patents and Disclaimers. |
You may re-distribute the Contributions you receive or your Derivative Works in source or executable form, subject to the following conditions: (1) You must provide the recipient with a copy of this License and retain the copyright, trademark, patent and disclaimer in the Contribution; and, (2) If you "distribute" a "Contribution" you have received, you must use this License to provide a source code copy of that "Contribution"; if you "distribute" your "Derivative Work", you must: (i) Provide the "corresponding source code" of your "Derivative Works" "distributed" using the "Derivative Works" with the "Derivative Works". If you provide the aforementioned "corresponding source code" through a download link, you should place the address of the download link in a conspicuous place in the "derivative work" or its accompanying documents, and the validity period will not be from the date of "distribution" of the "derivative work". less than three years and ensure that the "corresponding source code" is available to recipients; or, (ii) with the Derivative Works, provide recipients with a written offer that you are willing to provide the "corresponding source code" of your Derivative Works "distributed" under this License. The written offer should be placed in a prominent position in the "Derivative Works" and ensure that the recipients may obtain the "corresponding source code" under the written offer for no more than three months from the date of your receipt of the request, and to be valid from the date of Not less than three years from the date the Derivative Work is "distributed". |
Version 2 of the Mulan Public License has detailed rules for receiving "Contributions" and "Derivative Works".
By definition, "contribution" means:
Copyright-protected works licensed by Contributor under this License, including works initially licensed by Contributor under this License and subsequent works licensed by Contributor under this License "Derivative Works" under.
"Derivative Work" means:
Works based on Contributions, including works that are modified, rewritten, translated, annotated, combined, or linked (including dynamically or statically) to all or part of the Contributions. Works that only make inter-process communication or system calls with the Contribution are independent works and are not Derivative Works.
In terms of specific regulations, for the "contribution" received, the license must be used for secondary distribution. For "derivative works", not only need to use the license, but also need to provide the source code download address corresponding to the "derivative works" in an obvious location, and the validity period of the constraints is 3 years.
The original address of the Mulan series license: https://license.coscl.org.cn/MulanPubL-2.0/index.html