Welcome!

Linux Containers Authors: Derek Weeks, Liz McMillan, PagerDuty Blog, XebiaLabs Blog, Rishi Bhargava

Related Topics: Open Source Cloud, Linux Containers, Eclipse, Release Management , Apache, FinTech 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
In his General Session at 17th Cloud Expo, Bruce Swann, Senior Product Marketing Manager for Adobe Campaign, explored the key ingredients of cross-channel marketing in a digital world. Learn how the Adobe Marketing Cloud can help marketers embrace opportunities for personalized, relevant and real-time customer engagement across offline (direct mail, point of sale, call center) and digital (email, website, SMS, mobile apps, social networks, connected objects).
"My role is working with customers, helping them go through this digital transformation. I spend a lot of time talking to banks, big industries, manufacturers working through how they are integrating and transforming their IT platforms and moving them forward," explained William Morrish, General Manager Product Sales at Interoute, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York City, NY.
With the introduction of IoT and Smart Living in every aspect of our lives, one question has become relevant: What are the security implications? To answer this, first we have to look and explore the security models of the technologies that IoT is founded upon. In his session at @ThingsExpo, Nevi Kaja, a Research Engineer at Ford Motor Company, will discuss some of the security challenges of the IoT infrastructure and relate how these aspects impact Smart Living. The material will be delivered i...
SYS-CON Events announced today that Ocean9will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Ocean9 provides cloud services for Backup, Disaster Recovery (DRaaS) and instant Innovation, and redefines enterprise infrastructure with its cloud native subscription offerings for mission critical SAP workloads.
Your homes and cars can be automated and self-serviced. Why can't your storage? From simply asking questions to analyze and troubleshoot your infrastructure, to provisioning storage with snapshots, recovery and replication, your wildest sci-fi dream has come true. In his session at @DevOpsSummit at 20th Cloud Expo, Dan Florea, Director of Product Management at Tintri, will provide a ChatOps demo where you can talk to your storage and manage it from anywhere, through Slack and similar services ...
In his session at @ThingsExpo, Eric Lachapelle, CEO of the Professional Evaluation and Certification Board (PECB), will provide an overview of various initiatives to certifiy the security of connected devices and future trends in ensuring public trust of IoT. Eric Lachapelle is the Chief Executive Officer of the Professional Evaluation and Certification Board (PECB), an international certification body. His role is to help companies and individuals to achieve professional, accredited and worldw...
SYS-CON Events announced today that Linux Academy, the foremost online Linux and cloud training platform and community, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Linux Academy was founded on the belief that providing high-quality, in-depth training should be available at an affordable price. Industry leaders in quality training, provided services, and student certification passes, its goal is to c...
SYS-CON Events announced today that SoftLayer, an IBM Company, has been named “Gold Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2016, at the Javits Center in New York, New York. SoftLayer, an IBM Company, provides cloud infrastructure as a service from a growing number of data centers and network points of presence around the world. SoftLayer’s customers range from Web startups to global enterprises.
"delaPlex is a software development company. We do team-based outsourcing development," explained Mark Rivers, COO and Co-founder of delaPlex Software, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York City, NY.
SYS-CON Events announced today that CA Technologies has been named “Platinum Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY, and the 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business – from apparel to energy – is being rewritten by software. From ...
SYS-CON Events announced today that Technologic Systems Inc., an embedded systems solutions company, will exhibit at SYS-CON's @ThingsExpo, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Technologic Systems is an embedded systems company with headquarters in Fountain Hills, Arizona. They have been in business for 32 years, helping more than 8,000 OEM customers and building over a hundred COTS products that have never been discontinued. Technologic Systems’ pr...
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).
SYS-CON Events announced today that Loom Systems will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Founded in 2015, Loom Systems delivers an advanced AI solution to predict and prevent problems in the digital business. Loom stands alone in the industry as an AI analysis platform requiring no prior math knowledge from operators, leveraging the existing staff to succeed in the digital era. With offices in S...
SYS-CON Events announced today that HTBase will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. HTBase (Gartner 2016 Cool Vendor) delivers a Composable IT infrastructure solution architected for agility and increased efficiency. It turns compute, storage, and fabric into fluid pools of resources that are easily composed and re-composed to meet each application’s needs. With HTBase, companies can quickly prov...
SYS-CON Events announced today that T-Mobile will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. As America's Un-carrier, T-Mobile US, Inc., is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to 67.4 million customers who are unwilling to compromise on ...
SYS-CON Events announced today that Cloud Academy will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Cloud Academy is the industry’s most innovative, vendor-neutral cloud technology training platform. Cloud Academy provides continuous learning solutions for individuals and enterprise teams for Amazon Web Services, Microsoft Azure, Google Cloud Platform, and the most popular cloud computing technologies. Ge...
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 20th International Cloud Expo, which will take place on June 6–8, 2017, at the Javits Center in New York City, NY. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buyers...
SYS-CON Events announced today that Infranics will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Since 2000, Infranics has developed SysMaster Suite, which is required for the stable and efficient management of ICT infrastructure. The ICT management solution developed and provided by Infranics continues to add intelligence to the ICT infrastructure through the IMC (Infra Management Cycle) based on mathemat...
SYS-CON Events announced today that Interoute, owner-operator of one of Europe's largest networks and a global cloud services platform, has been named “Bronze Sponsor” of SYS-CON's 20th Cloud Expo, which will take place on June 6-8, 2017 at the Javits Center in New York, New York. Interoute is the owner-operator of one of Europe's largest networks and a global cloud services platform which encompasses 12 data centers, 14 virtual data centers and 31 colocation centers, with connections to 195 add...
SYS-CON Events announced today that SD Times | BZ Media has been named “Media Sponsor” of SYS-CON's 20th International Cloud Expo, which will take place on June 6–8, 2017, at the Javits Center in New York City, NY. BZ Media LLC is a high-tech media company that produces technical conferences and expositions, and publishes a magazine, newsletters and websites in the software development, SharePoint, mobile development and commercial UAV markets.