Multi-licensing

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الموسوعة الحرة

Multi-licensing is the practice of distributing software under two or more different sets of terms and conditions. This may mean multiple different software licenses or sets of licenses. Prefixes may be used to indicate the number of licenses used, e.g. dual-licensed for software licensed under two different licenses.

When software is multi-licensed, recipients can typically choose the terms under which they want to use or distribute the software, but the simple presence of multiple licenses in a software package or library does not necessarily indicate that the recipient can freely choose one or the other. In some cases, especially when the software has multiple origins, all the accompanied licenses apply at the same time. The applicability of the different licenses has to be individually checked. The distributor may or may not apply a fee to either option. The two usual motivations for multi-licensing are license compatibility[1] and market segregation based business models.[2]

Business models

Multi-licensing is commonly done to support free software business models in a commercial environment. In this scenario, one option is a proprietary software license, which allows the possibility of creating proprietary applications derived from it, while the other license is a copyleftfree software/open-source license, thus requiring any derived work to be released under the same license. The copyright holder of the software then typically provides the free version of the software at little or no cost, and profits by selling proprietary licenses to commercial operations looking to incorporate the software into their own business. This model can be compared to shareware.[3][4]

Since in most cases, only the copyright holder can change the licensing terms of a software, multi licensing is mostly used by companies that wholly own the software which they are licensing. Confusion may arise when a person outside the company creates additional source code, using the less restrictive license. Because the company with the official code is not the copyright holder of the additional code, they may not legally include this new work in their more restrictively licensed version. Companies may require outside developers agree to a contributor license agreement before accepting their work in the official code-base and source code repositories.[5]

يستخدم أصحاب حقوق الطبع والنشر لبعض حزم البرامج المجانية نظام الترخيص المتعدد ، معلنين استعدادهم لتوزيعها باستخدام ترخيص برمجيات حرة محمي بحقوق الطبع والنشر ، وترخيص برمجيات غير حرة. يمنح الترخيص الأخير المستخدمين عادةً البرنامج كبرنامج احتكاري ، أو يمنح أطرافًا ثالثة شفرة المصدر دون شروط حقوق الطبع والنشر. في هذه الحالة، يمارس أصحاب حقوق الطبع والنشر احتكارهم الذي يمنحهم إياه القانون ، كما يستخدمون الترخيص المتعدد لتمييز الحقوق والحريات التي يحصل عليها مختلف المستفيدين.

يُتيح هذا النوع من التراخيص لحاملها تقديم تعديلات وإصدارات مبكرة، وإنشاء أعمال مشتقة أخرى، أو منح حقوق إعادة توزيع النسخ الاحتكارية لأطراف ثالثة، مع توفير نسخة مجانية من البرنامج للجميع. ويمكن أن يُفيد نشر البرنامج كبرنامج حرّ مرخص بحقوق النسخ صاحب حقوق النشر من خلال تلقي مساهمات من مستخدمي ومطوري مجتمع البرمجيات الحرة . وتشمل هذه المساهمات دعم مجتمع مستخدمين مُتخصص، والتسويق الشفهي ، أو التعديلات المُتاحة وفقًا لشروط ترخيص حقوق النسخ. ومع ذلك، فإن التزام صاحب حقوق النشر بالتحايل على أحكام حقوق النسخ والترويج لإعادة التوزيع الاحتكارية يُعرّضه لخطر فقدان ثقة ودعم مستخدمي البرمجيات الحرة. [ 6 ] [ 7 ]

ومن أمثلة البرامج متعددة التراخيص: بيئة تطوير NetBeans من Oracle ، وقاعدة بيانات MySQL AB ، و Asterisk ، وقاعدة بيانات Berkeley من Oracle Corporation ، وModelio ، وIce من ZeroC ، و Magnolia CMS ، وJUCE ، و wolfSSL ، [ 8 ] ومجموعة أدوات تطوير Qt من Qt Software .

Description on one specific example to illustrate multi-licensing: Oracle MySQL comes in various editions: MySQL Enterprise Edition[9] is a commercial edition, hence to be purchased. The license is only offered as a subscription, named MySQL Enterprise Edition Subscription. The same applies for MySQL Standard Edition (MySQL Standard Edition Subscription) and MySQL Cluster CGE (MySQL Cluster Carrier Grade Edition Subscription). The other editions, such as the MySQL Classic Edition or MySQL Community Edition, are free to use with some restrictions. For instance, the MySQL Community Edition is a freely downloadable version, available under the GPL license and is supported by a community of open source developers.[10]

Single-vendor commercial open source business model

The term single-vendor commercial open source was coined by Dirk Riehle in 2010,[11][12] and has later been further popularized by other scholars, such as Simon R. B. Berdal.[13]

According to Riehle:

Single-vendor commercial open source firms build their business around an open source software project that they fully control, typically by having developed the software and never having shared control with third parties. This is done by owning the full copyright to the code and related intellectual property such as patents and trademarks... Typically, the free open source form is provided under a reciprocal license like the GPL to drive adoption but stall possible competitors. Paid-for versions of the software are then provided under a commercial license like traditional software vendors do. This is also known as the dual-license strategy of commercial open source.[11]

In contrast to traditional open source projects, a single-vendor commercial open source project is controlled by exactly one stakeholder with the purpose of commercially exploiting it.[11] In this context, the open source community is less engaged in the development of core functionality, as they typically are in conventional (pure) open source projects. As the then CEO Mårten Mikos of MySQL said in an interview:

The depth of the contributions varies by product and situation. The deeper you go into the core of the database engine, the more difficult it is for somebody to contribute because it takes five years to learn. If you build something on the outskirts of the kernel - some tool or function that you add on top of it - then that is much easier because there's less risk that you will mess up the whole product. But something great can emerge out of many tiny-looking contributions. It's analogous to how, in economic development, microloans can have such a huge impact - each entry is minimal, but when you multiply it by the number of people who are involved, it grows massive. It starts getting a momentum of its own..[14]

Hence, the community of multi-license software as a rule includes employees of the code-owning firm, as well as strategic partners that have vested interest in the software. As Riehle notes, In single-vendor open source, almost all of the core product development work is carried out by the commercial firm, with occasional contributions from the community.[11]

As Berdal notes, the governance of the open source community becomes a key business management process in this context: As such, it needs to be aligned with other business activities. Governance models of dual-licensed OSS editions may therefore display a tendency towards commercial bias. To prevent the community from being provoked or alienated it may therefore seem imperative to balance commercial inclinations against “open” interests.[13] This is by no means an easy task. As Berdal demonstrated through a case study of SugarCRM, this commercial open source software (COSS) business model can trigger substantial friction points, which can eventually lead to pure open source forks (table adapted from Berdal, Table 3, page 75[13]):

Friction pointCOSS/SugarCRM perspectivesOpposing FOSS perspectives
Copyright assignmentPrecondition for dual licensing, without which the business model would not be commercially sustainable.Disincentive to contribute because of fears of going (partially) private.

Free Software purists: “Immoral”.

Withholding of value driving functionality from Sugar CE1) Pre-emptive competitive advantage against OSS clones,

2) wider scope for price discrimination and product differentiation for commercial editions, and 3) stronger incentives for Sugar CE users to migrate to a commercial edition.

"Crippleware" / damaged good, "open core". Disincentive to contribute because of lacking assurances against potentially exclusive proprietary use.
"Powered by SugarCRM" logo1) Official stance: Legitimate author attribution in recognition of invested work.

Not confirmed, but highly plausible: 2) brand promotion, and 3) thwart forking attempts / stifle unsolicited external code reuse.

"Badgeware". Violation of basic FOSS principles, especially when coupled with the SugarCRM Trademark Policy.
"Closed" governance practices, even restrictive by COSS standards1) Need for managerial control to ensure that customers’ needs are efficiently met.

2) Speculative: Diminish the influence of FOSS enthusiasts and vigilantes, who could interfere with a commercially guided development process.

Overly restrictive, lack of procedural fairness. No real influence over shared Sugar CE code base.

De facto relegation to work on small-scale peripheral complements, which not need to be open source.

Preferential treatment of commercially affiliated community constituents and third partiesReasonable supplementary approach of differentiation to utilize and enhance commercially vested interests in SugarCRM’s product platform. This is 1) to strengthen the firm’s sales channels through a co-evolution of capabilities with partners, and to 2) stimulate demand driven customization and development of modular complements (extensions, plug-ins etc.), 3) triggering network effects which increase the overall value of the product platform.Deficient distributional fairness (in terms of underprovided focus and priority). Perception of being kept out of the loop.

Only a few months after these friction points were observed, a new fork of the SugarCRM Community Edition was announced.

License compatibility

Source:[15]

A second use of multi-licensing with free software is for license compatibility,[1] allowing code from differently licensed free software projects to be combined, or to provide users the preference to pick a license.

تشمل الأمثلة شفرة المصدر لمجموعة تطبيقات موزيلا ، وموزيلا ثندربيرد وموزيلا فايرفوكس سابقًا ، والتي استخدمت ترخيصًا ثلاثيًا بموجب رخصة موزيلا العامة (MPL) 1.1، ورخصة جنو العمومية العامة (GPL) 2.0، أو رخصة جنو العمومية الصغرى (LGPL) 2.1 [ 16 ] قبل أن تتم ترقية الأخيرة إلى رخصة موزيلا العامة المتوافقة مع رخصة جنو العمومية العامة ( MPL) 2.0، مما جعل الترخيص الثلاثي غير ضروري. [ 17 ] ومن الأمثلة الأخرى لغة بيرل ، المرخصة بترخيص مزدوج بموجب رخصة جنو العمومية العامة (GPL) أو الرخصة الفنية ، [ 18 ] ولغة روبي ، التي يتضمن ترخيصها ترخيصًا مزدوجًا صريحًا بموجب رخصة جنو العمومية العامة (GPL).

الفصل السوقي في البرمجيات الاحتكارية

يستخدم موزعو البرامج غير المجانية نظام الترخيص المتعدد. ويُطبق هذا النظام أحيانًا على البرامج الاحتكارية لتقسيم السوق. فمن خلال تقسيم العملاء إلى فئات متعددة، مثل المستخدمين المنزليين والمستخدمين المحترفين والأكاديميين، يستطيع أصحاب حقوق النشر تحديد أسعار مختلفة لكل فئة. مع ذلك، من الشائع بين شركات البرامج الاحتكارية إصدار "نسخة منزلية" و"نسخة احترافية" من المنتج نفسه، وتختلف هاتان النسختان في البرنامج وميزاته، وليس فقط في الترخيص.

انظر أيضاً

مراجع

  1. 1 2 نيكولاي بيزروكوف (2001). "المزايا النسبية لرخص GPL وBSD وArtistic (نقد الطبيعة الفيروسية لرخصة GPL الإصدار 2 - أو دفاعًا عن فكرة الترخيص المزدوج)" . مؤرشف من الأصل في 22 ديسمبر 2001. تحفز الخاصية الفيروسية انتشار الرخص وتساهم في "الكابوس المفروض برخصة GPL" - وهو وضع تكون فيه العديد من الرخص الأخرى غير متوافقة منطقيًا مع رخصة GPL وتجعل الحياة صعبة بلا داعٍ للمطورين الذين يعملون في بيئة Linux (KDE مثال جيد هنا، وPython مثال أقل شهرة).
  2. ↑Ronacher, Armin (July 23, 2013). "Licensing in a Post Copyright World". lucumr.pocoo.org. Retrieved November 18, 2015. The AGPLv3 was a terrible success, especially among the startup community that found the perfect base license to make dual licensing with a commercial license feasible. MongoDB, RethinkDB, OpenERP, SugarCRM as well as WURFL all now utilize the AGPLv3 as a vehicle for dual commercial licensing. The AGPLv3 makes that generally easy to accomplish as the original copyright author has the rights to make a commercial license possible but nobody who receives the sourcecode itself through the APLv3 inherits that right. I am not sure if that was the intended use of the license, but that's at least what it's definitely being used for now.
  3. ↑Linux News: Tech Buzz: Dual Licensing: Having Your Cake and Eating It Too
  4. ↑Dual-Licensing Open Source Business Models | Linux
  5. ↑Digium Incorporated. "Asterisk Guidelines, The contributor license agreement". Retrieved February 10, 2009.
  6. ↑Netscape Public License - GNU Project - Free Software Foundation (FSF)
  7. ↑FSF's Opinion on the Apple Public Source License (APSL) - GNU Project - Free Software Foundation (FSF)
  8. ↑"wolfSSL Embedded SSL/TLS Library | Now Supporting TLS 1.3". Retrieved January 27, 2020.
  9. ↑"My SQL Enterprise Edition". Oracle. Retrieved April 25, 2013.
  10. ↑"MySQL Community Edition". Oracle, MySQL. Retrieved April 25, 2013.
  11. 1234The Single-Vendor Commercial Open Source Business Model, November 9, 2010, retrieved December 8, 2013
  12. ↑Riehle, Dirk (March 2012). "The single-vendor commercial open source business model". Information Systems and E-Business Management. 10 (1): 5–17. doi:10.1007/s10257-010-0149-x.
  13. 123Berdal, S.R.B. (January 2013). "Peculiarities of the Commercial Open Source business model: Case study of SugarCRM". 112. Tronheim, Norway.
  14. ↑"The Oh-So-Practical Magic of Open-Source Innovation". MIT Sloan Management Review. 50 (1). October 1, 2008. Retrieved December 8, 2013.
  15. ↑"Mozilla Public License, version 2.0". www.mozilla.org. Retrieved April 6, 2025.
  16. ↑Mozilla Foundation. "Mozilla Code Licensing". Retrieved September 17, 2007.
  17. ↑"MPL 2 Upgrade". Retrieved August 18, 2012.
  18. ↑The Perl Foundation. "Perl Licensing - perl.org". Retrieved September 17, 2007.