Welcome!

Apache Authors: Pat Romanski, Liz McMillan, Elizabeth White, Janakiram MSV, Gil Allouche

Related Topics: Open Source Cloud, Linux Containers, Eclipse, Release Management , Apache, OpenStack Journal

Open Source Cloud: Article

Which Open Source Software License Should I Use?

There are different considerations for every project

I've recently been involved in several discussions that are variations on, "Which open source or free software license should I choose for my project?" Here is my way of looking at the large and growing collection of licenses in the wild. First let's make sure we all understand that I Am Not A Lawyer. This is not legal advice. Depending upon your needs and your comfort with risk around your software, you'll want to confirm your legal choices with counsel in your jurisdiction.

The first and obvious consideration is whether or not the license is approved as an open source license by the Open Source Initiative (OSI). The OSI created the Open Source Definition in the late 1990s as a set of attributes that a software license must support to be considered "open source". Anyone can take a license to the OSI for debate and discussion and if approved as meeting the OSD, then the license is added to the canonical list.

While this seems an obvious place to start, I was recently surprised to discover a license called the "Clear BSD License." It attempts to clarify explicitly that patents are not being discussed in the license. It is not on the OSI list (while the New BSD and Simplified BSD licenses are) and is therefore not worth considering. Inventing new licenses as small derivatives of existing licenses is not helpful and creates costly legal busy work. There exists a broad collection of OSI-approved licenses today. These licenses cover millions of lines of software involved in billions of dollars in procurement. One would be hard pressed to describe a serious set of circumstances that isn't already covered by an OSI-approved license.

There are several big levers available when considering an open source license:

  • How much license reciprocity is required with respect to the software, modifications, and any derivatives someone develops?
  • What is said about patent licensing and litigation?
  • What legal jurisdiction covers the license?

The reciprocity issue is all about "copyleft" and whether or not using the software source code attaches the license to the modifications and derivatives, and whether the source code to those modifications and derivatives needs to be published.

On one end of the spectrum are licenses that have no copyleft requirements. These licenses essentially allow anyone to use the software in anyway without requiring much more than maintaining copyrights. Licenses that fall into this set include the New and Simplified BSD licenses, the MIT license, and the Apache 2.0 and Microsoft Permissive licenses.

There are a set of licenses that maintain a sense of copyleft around the software itself but support the use of the software in larger works of software which may contain software that is licensed differently (e.g. closed and proprietary). These licenses include the Eclipse Public License, the newer Mozilla Public License 2.0, and the Microsoft Reciprocal License.

On the other end of the copyleft spectrum are strong copyleft licenses. Software freedom is defined by the Free Software Foundation in terms of the freedoms a user of software must have. Strong copyleft supports software freedom. Many developers support software freedom, and demonstrate this support using one of the family of GPL licenses (GPL2.0, GPL3.0, and the Affero GPL3.0) as a way to ensure the strongest copyleft and strongest license attachment when the software in question is used in building and distributing other software.

Software patents weren't really an issue when software was beginning to be widely shared on the early Internet and so weren't mentioned in the early licenses. By the late 1990s, software patents were on the rise and corporate legal teams were becoming more involved in the writing of open source licenses as they became more involved with open source software and developing the open source foundations around evolving projects. The Apache 2.0 License, Mozilla Public License 2.0, Eclipse Public License, the newer GPL licenses, and both Microsoft licenses reflect this shift in language. Each license explicitly talks about patent licenses. Each license has language that covers patent litigation to varying degrees.

I mention legal jurisdiction in the big levers category because some licenses explicitly mention it and this can be a real show stopper for some people. For that reason alone I treat it as a Big Lever. (The Mozilla Public License 2.0 specifically tries to deal with jurisdiction as one of changes from the original MPL, as that was often a criticism of the earlier license.)

Other considerations in license choice include:

  • Are there project specific affinities?
  • History of the license and foundation/corporate/commercial involvement?

The "language" projects (Perl, PHP, Python) each have their own licenses (Artistic License 2.0, PHP License 3.0, and Python License 2.0 respectively). If you are working on a project that closely ties to a specific open source programming language community then you should obviously consider that community's license as the question of mixing modules and dependencies will be simplified with respect to open source license.

As software IP law has evolved and the Internet has become an enormous space for people to collaborate on software development, commercial organizations became involved. We have seen the creation of open source software foundations with specific licenses associated with them. Corporate legal teams have become involved in authoring open source licenses, and the language and structure of these licenses (e.g. terminology and definitions) reflects this involvement. Lawyers without a lot of experience in open source licenses may feel more comfortable reviewing these newer licenses.

So to recap, presuming that your primary motivation is to co-develop and collaborate on an open source project, in my way of looking at open source licenses your choices break down roughly as follows. (I'm keeping the discussion here to widely used licenses, and/or licenses where large commercial organizations with conservative counsel or neutral non-profit open source foundations had a hand in their creation.)

If you want to allow anyone to do anything at any time with the software, use the MIT or new (3-clause) BSD license, i.e. no copyleft and no discussion of patents. Both of these licenses came from the academic world, and both from a period of time where software patents were not a focus.

If you want to allow anyone to do anything with the software (so no copyleft), but feel something needs to be said about patents and license termination in the face of litigation, and/or you want a license that corporate counsel is more comfortable reading then look at either the Apache 2.0 license or possibly the Microsoft Permissive License. These licenses were written to continue to encourage a completely open sharing environment but were written with a more corporate view (note the structure and language), and both begin to cover patents with varying (and subtly different) degrees of patent retaliation built into them.

If you feel others should be able to build [possibly product] around your software, but want to ensure changes to the core software project itself remain open source (i.e. the changes must be published), you likely want to look to either the Eclipse Public License, the newer Mozilla Public License 2.0 or the Microsoft Reciprocal License. These are modern licenses developed from commercial/corporate perspectives supporting "weak" copyleft. [N.B. The EPL does name NY State as the jurisdiction.] Pay attention to patent statements in each.

If you are a firm supporter of software freedom or want to ensure that if your software source is used anywhere that the resulting derivatives are maximally published as open source ensuring software freedom then you should look to GPL2.0 or GPL3.0 depending upon your needs.

There are a couple of interesting side ideas I've come across in the open source licensing space as different projects wrestled with how best to create the "right" licensing for their software.

  • Many companies are concerned about their patent portfolios when creating open source projects. Google took an interesting approach to the problem when they released the WebM project. They chose the New BSD license and then created a very specific "Additional IP Rights Grant" to cover the patent language they needed.
  • It is the nature of IP law that the owner of the property can license it as many ways to as many people as they choose. This is why the Microsoft EULA for a personal copy of the Windows operating system is different from an Enterprise License Agreement and how MySQL AB developed a line of business around closed software licensing as well as their GPL-licensed project. In the early days (up through PHP3), the software from the PHP project was similarly "dual" licensed under both the GPL2.0 and an earlier PHP license to allow the software to be included in as many places as possible because the GPL was not directly compatible with the PHP license of the time.

I have deliberately not tried to create a table or decision tree for license choice here. I believe there are sufficient edges and nuances to license choice that it can never be properly "automated" with the licenses we have today that reflect their rich background of needs and history. There is always one more legal question of "what about the situation when ...?" Such questions will likely involve legal counsel and may be very jurisdiction sensitive.

Likewise, open source software licenses don't simply reflect a set of legal choices. In the early stage of an open source project when the author or authors are first publishing the software, the choice of license reflects as much of the social contract that is being made for the project as any legal requirements. It is the first governance document of the early possible community that comes into play long before formal governance, mission statements, and codes of conduct may be created around growing community.

Full text of all the licenses can be found on the Open Source Initiative at:http://opensource.org/licenses/alphabetical

Excellent information on how to consider various software licenses in combination with the GPL can be found here: http://www.gnu.org/licenses/license-list.html#SoftwareLicenses

If you need to get a lawyer up to speed, consider pointing them to: http://www.ifosslr.org/ifosslr

More Stories By Stephen Walli

Stephen Walli has worked in the IT industry since 1980 as both customer and vendor. He is presently the technical director for the Outercurve Foundation.

Prior to this, he consulted on software business development and open source strategy, often working with partners like Initmarketing and InteropSystems. He organized the agenda, speakers and sponsors for the inaugural Beijing Open Source Software Forum as part of the 2007 Software Innovation Summit in Beijing. The development of the Chinese software market is an area of deep interest for him. He is a board director at eBox, and an advisor at Bitrock, Continuent, Ohloh (acquired by SourceForge in 2009), and TargetSource (each of which represents unique opportunities in the FOSS world). He was also the open-source-strategist-in-residence for Open Tuesday in Finland.

Stephen was Vice-president, Open Source Development Strategy at Optaros, Inc. through its initial 19 months. Prior to that he was a business development manager in the Windows Platform team at Microsoft working on community development, standards, and intellectual property concerns.

@ThingsExpo Stories
Internet of @ThingsExpo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with the 19th International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world and ThingsExpo Silicon Valley Call for Papers is now open.
Cognitive Computing is becoming the foundation for a new generation of solutions that have the potential to transform business. Unlike traditional approaches to building solutions, a cognitive computing approach allows the data to help determine the way applications are designed. This contrasts with conventional software development that begins with defining logic based on the current way a business operates. In her session at 18th Cloud Expo, Judith S. Hurwitz, President and CEO of Hurwitz & ...
SYS-CON Events announced today that ReadyTalk, a leading provider of online conferencing and webinar services, has been named Vendor Presentation Sponsor at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. ReadyTalk delivers audio and web conferencing services that inspire collaboration and enable the Future of Work for today’s increasingly digital and mobile workforce. By combining intuitive, innovative tec...
There is growing need for data-driven applications and the need for digital platforms to build these apps. In his session at 19th Cloud Expo, Muddu Sudhakar, VP and GM of Security & IoT at Splunk, will cover different PaaS solutions and Big Data platforms that are available to build applications. In addition, AI and machine learning are creating new requirements that developers need in the building of next-gen apps. The next-generation digital platforms have some of the past platform needs a...
Almost two-thirds of companies either have or soon will have IoT as the backbone of their business in 2016. However, IoT is far more complex than most firms expected. How can you not get trapped in the pitfalls? In his session at @ThingsExpo, Tony Shan, a renowned visionary and thought leader, will introduce a holistic method of IoTification, which is the process of IoTifying the existing technology and business models to adopt and leverage IoT. He will drill down to the components in this fra...
SYS-CON Events announced today that Pulzze Systems will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Pulzze Systems, Inc. provides infrastructure products for the Internet of Things to enable any connected device and system to carry out matched operations without programming. For more information, visit http://www.pulzzesystems.com.
I'm a lonely sensor. I spend all day telling the world how I'm feeling, but none of the other sensors seem to care. I want to be connected. I want to build relationships with other sensors to be more useful for my human. I want my human to understand that when my friends next door are too hot for a while, I'll soon be flaming. And when all my friends go outside without me, I may be left behind. Don't just log my data; use the relationship graph. In his session at @ThingsExpo, Ryan Boyd, Engi...
The Transparent Cloud-computing Consortium (abbreviation: T-Cloud Consortium) will conduct research activities into changes in the computing model as a result of collaboration between "device" and "cloud" and the creation of new value and markets through organic data processing High speed and high quality networks, and dramatic improvements in computer processing capabilities, have greatly changed the nature of applications and made the storing and processing of data on the network commonplace.
From wearable activity trackers to fantasy e-sports, data and technology are transforming the way athletes train for the game and fans engage with their teams. In his session at @ThingsExpo, will present key data findings from leading sports organizations San Francisco 49ers, Orlando Magic NBA team. By utilizing data analytics these sports orgs have recognized new revenue streams, doubled its fan base and streamlined costs at its stadiums. John Paul is the CEO and Founder of VenueNext. Prior ...
In his general session at 18th Cloud Expo, Lee Atchison, Principal Cloud Architect and Advocate at New Relic, discussed cloud as a ‘better data center’ and how it adds new capacity (faster) and improves application availability (redundancy). The cloud is a ‘Dynamic Tool for Dynamic Apps’ and resource allocation is an integral part of your application architecture, so use only the resources you need and allocate /de-allocate resources on the fly.
SYS-CON Events announced today that Numerex Corp, a leading provider of managed enterprise solutions enabling the Internet of Things (IoT), will exhibit at the 19th International Cloud Expo | @ThingsExpo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Numerex Corp. (NASDAQ:NMRX) is a leading provider of managed enterprise solutions enabling the Internet of Things (IoT). The Company's solutions produce new revenue streams or create operating...
WebRTC adoption has generated a wave of creative uses of communications and collaboration through websites, sales apps, customer care and business applications. As WebRTC has become more mainstream it has evolved to use cases beyond the original peer-to-peer case, which has led to a repeating requirement for interoperability with existing infrastructures. In his session at @ThingsExpo, Graham Holt, Executive Vice President of Daitan Group, will cover implementation examples that have enabled ea...
IoT offers a value of almost $4 trillion to the manufacturing industry through platforms that can improve margins, optimize operations & drive high performance work teams. By using IoT technologies as a foundation, manufacturing customers are integrating worker safety with manufacturing systems, driving deep collaboration and utilizing analytics to exponentially increased per-unit margins. However, as Benoit Lheureux, the VP for Research at Gartner points out, “IoT project implementers often ...
The Jevons Paradox suggests that when technological advances increase efficiency of a resource, it results in an overall increase in consumption. Writing on the increased use of coal as a result of technological improvements, 19th-century economist William Stanley Jevons found that these improvements led to the development of new ways to utilize coal. In his session at 19th Cloud Expo, Mark Thiele, Chief Strategy Officer for Apcera, will compare the Jevons Paradox to modern-day enterprise IT, e...
Complete Internet of Things (IoT) embedded device security is not just about the device but involves the entire product’s identity, data and control integrity, and services traversing the cloud. A device can no longer be looked at as an island; it is a part of a system. In fact, given the cross-domain interactions enabled by IoT it could be a part of many systems. Also, depending on where the device is deployed, for example, in the office building versus a factory floor or oil field, security ha...
SYS-CON Events announced today the Enterprise IoT Bootcamp, being held November 1-2, 2016, in conjunction with 19th Cloud Expo | @ThingsExpo at the Santa Clara Convention Center in Santa Clara, CA. Combined with real-world scenarios and use cases, the Enterprise IoT Bootcamp is not just based on presentations but with hands-on demos and detailed walkthroughs. We will introduce you to a variety of real world use cases prototyped using Arduino, Raspberry Pi, BeagleBone, Spark, and Intel Edison. Y...
Is your aging software platform suffering from technical debt while the market changes and demands new solutions at a faster clip? It’s a bold move, but you might consider walking away from your core platform and starting fresh. ReadyTalk did exactly that. In his General Session at 19th Cloud Expo, Michael Chambliss, Head of Engineering at ReadyTalk, will discuss why and how ReadyTalk diverted from healthy revenue and over a decade of audio conferencing product development to start an innovati...
Fifty billion connected devices and still no winning protocols standards. HTTP, WebSockets, MQTT, and CoAP seem to be leading in the IoT protocol race at the moment but many more protocols are getting introduced on a regular basis. Each protocol has its pros and cons depending on the nature of the communications. Does there really need to be only one protocol to rule them all? Of course not. In his session at @ThingsExpo, Chris Matthieu, co-founder and CTO of Octoblu, walk you through how Oct...
SYS-CON Events announced today that Bsquare has been named “Silver Sponsor” of SYS-CON's @ThingsExpo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. For more than two decades, Bsquare has helped its customers extract business value from a broad array of physical assets by making them intelligent, connecting them, and using the data they generate to optimize business processes.
Identity is in everything and customers are looking to their providers to ensure the security of their identities, transactions and data. With the increased reliance on cloud-based services, service providers must build security and trust into their offerings, adding value to customers and improving the user experience. Making identity, security and privacy easy for customers provides a unique advantage over the competition.