Welcome!

Linux Containers Authors: Liz McMillan, Lori MacVittie, Carmen Gonzalez, Pat Romanski, Elizabeth White

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
Unsecured IoT devices were used to launch crippling DDOS attacks in October 2016, targeting services such as Twitter, Spotify, and GitHub. Subsequent testimony to Congress about potential attacks on office buildings, schools, and hospitals raised the possibility for the IoT to harm and even kill people. What should be done? Does the government need to intervene? This panel at @ThingExpo New York brings together leading IoT and security experts to discuss this very serious topic.
Internet of @ThingsExpo has announced today that Chris Matthieu has been named tech chair of Internet of @ThingsExpo 2017 New York The 7th Internet of @ThingsExpo will take place on June 6-8, 2017, at the Javits Center in New York City, New York. Chris Matthieu is the co-founder and CTO of Octoblu, a revolutionary real-time IoT platform recently acquired by Citrix. Octoblu connects things, systems, people and clouds to a global mesh network allowing users to automate and control design flo...
Everyone knows that truly innovative companies learn as they go along, pushing boundaries in response to market changes and demands. What's more of a mystery is how to balance innovation on a fresh platform built from scratch with the legacy tech stack, product suite and customers that continue to serve as the business' foundation. In his General Session at 19th Cloud Expo, Michael Chambliss, Head of Engineering at ReadyTalk, discussed why and how ReadyTalk diverted from healthy revenue and mor...
SYS-CON Events has announced today that Roger Strukhoff has been named conference chair of Cloud Expo and @ThingsExpo 2017 New York. The 20th Cloud Expo and 7th @ThingsExpo will take place on June 6-8, 2017, at the Javits Center in New York City, NY. "The Internet of Things brings trillions of dollars of opportunity to developers and enterprise IT, no matter how you measure it," stated Roger Strukhoff. "More importantly, it leverages the power of devices and the Internet to enable us all to im...
Information technology is an industry that has always experienced change, and the dramatic change sweeping across the industry today could not be truthfully described as the first time we've seen such widespread change impacting customer investments. However, the rate of the change, and the potential outcomes from today's digital transformation has the distinct potential to separate the industry into two camps: Organizations that see the change coming, embrace it, and successful leverage it; and...
The 20th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held June 6-8, 2017, at the Javits Center in New York City, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Containers, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal ...
20th Cloud Expo, taking place June 6-8, 2017, at the Javits Center in New York City, NY, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy.
You have great SaaS business app ideas. You want to turn your idea quickly into a functional and engaging proof of concept. You need to be able to modify it to meet customers' needs, and you need to deliver a complete and secure SaaS application. How could you achieve all the above and yet avoid unforeseen IT requirements that add unnecessary cost and complexity? You also want your app to be responsive in any device at any time. In his session at 19th Cloud Expo, Mark Allen, General Manager of...
DevOps is being widely accepted (if not fully adopted) as essential in enterprise IT. But as Enterprise DevOps gains maturity, expands scope, and increases velocity, the need for data-driven decisions across teams becomes more acute. DevOps teams in any modern business must wrangle the ‘digital exhaust’ from the delivery toolchain, "pervasive" and "cognitive" computing, APIs and services, mobile devices and applications, the Internet of Things, and now even blockchain. In this power panel at @...
Bert Loomis was a visionary. This general session will highlight how Bert Loomis and people like him inspire us to build great things with small inventions. In their general session at 19th Cloud Expo, Harold Hannon, Architect at IBM Bluemix, and Michael O'Neill, Strategic Business Development at Nvidia, discussed the accelerating pace of AI development and how IBM Cloud and NVIDIA are partnering to bring AI capabilities to "every day," on-demand. They also reviewed two "free infrastructure" pr...
Financial Technology has become a topic of intense interest throughout the cloud developer and enterprise IT communities. Accordingly, attendees at the upcoming 20th Cloud Expo at the Javits Center in New York, June 6-8, 2017, will find fresh new content in a new track called FinTech.
"Dice has been around for the last 20 years. We have been helping tech professionals find new jobs and career opportunities," explained Manish Dixit, VP of Product and Engineering at Dice, in this SYS-CON.tv interview at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
An IoT product’s log files speak volumes about what’s happening with your products in the field, pinpointing current and potential issues, and enabling you to predict failures and save millions of dollars in inventory. But until recently, no one knew how to listen. In his session at @ThingsExpo, Dan Gettens, Chief Research Officer at OnProcess, discussed recent research by Massachusetts Institute of Technology and OnProcess Technology, where MIT created a new, breakthrough analytics model for ...
"At ROHA we develop an app called Catcha. It was developed after we spent a year meeting with, talking to, interacting with senior citizens watching them use their smartphones and talking to them about how they use their smartphones so we could get to know their smartphone behavior," explained Dave Woods, Chief Innovation Officer at ROHA, in this SYS-CON.tv interview at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
"ReadyTalk is an audio and web video conferencing provider. We've really come to embrace WebRTC as the platform for our future of technology," explained Dan Cunningham, CTO of ReadyTalk, in this SYS-CON.tv interview at WebRTC Summit at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
Whether your IoT service is connecting cars, homes, appliances, wearable, cameras or other devices, one question hangs in the balance – how do you actually make money from this service? The ability to turn your IoT service into profit requires the ability to create a monetization strategy that is flexible, scalable and working for you in real-time. It must be a transparent, smoothly implemented strategy that all stakeholders – from customers to the board – will be able to understand and comprehe...
In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, provided an overview of the evolution of the Internet and the Database and the future of their combination – the Blockchain. Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life sett...
Successful digital transformation requires new organizational competencies and capabilities. Research tells us that the biggest impediment to successful transformation is human; consequently, the biggest enabler is a properly skilled and empowered workforce. In the digital age, new individual and collective competencies are required. In his session at 19th Cloud Expo, Bob Newhouse, CEO and founder of Agilitiv, drew together recent research and lessons learned from emerging and established compa...
The WebRTC Summit New York, to be held June 6-8, 2017, at the Javits Center in New York City, NY, announces that its Call for Papers is now open. Topics include all aspects of improving IT delivery by eliminating waste through automated business models leveraging cloud technologies. WebRTC Summit is co-located with 20th International Cloud Expo and @ThingsExpo. WebRTC is the future of browser-to-browser communications, and continues to make inroads into the traditional, difficult, plug-in web co...
WebRTC is the future of browser-to-browser communications, and continues to make inroads into the traditional, difficult, plug-in web communications world. The 6th WebRTC Summit continues our tradition of delivering the latest and greatest presentations within the world of WebRTC. Topics include voice calling, video chat, P2P file sharing, and use cases that have already leveraged the power and convenience of WebRTC.