Center for Advanced Study & Research on Innovation Policy


CASRIP Newsletter - Summer 2007, Volume 14, Issue 3

Introduction to the Simple Public License

By James Sfekas[*]

Free Software and Open Source Software (collectively, FOSS) are common terms for software in which the developers make the source code publicly available. Because the source code is available, the software can be developed through the collaboration of volunteers throughout the world. These volunteers coordinate through the Internet, with each person contributing a small piece to the whole. FOSS principles have been adopted by a number of large companies, including IBM and Sun Microsystems. These companies have released many of their products to the public under various FOSS licenses, and in some cases have assigned employees to contribute to the development of particular programs. Many well-known products have been developed in this way, including the Linux operating system, the Apache web server, and the Firefox web browser.

The GNU General Public License[1] (GPL) was one of the earliest of these licenses and is the most well-known. Its most famous element is the so-called copyleft, which requires that anyone making a derivative work from GPL-licensed code must also license that code under the GPL. The current version of the GPL was released in 1991 and has been applied to many of the most famous FOSS products, including Linux and Firefox. A new version, 3.0, is currently in development.

In 1998, leading members of the FOSS movement created the Open Source Initiative in order to bring some structure to the movement. As part of this effort, they created the Open Source Definition[2] (OSD) to define what licenses would qualify as “Open Source.” Foremost among the requirements of the OSD is that all open source licenses should mandate that anyone distributing the program must also make the program’s source code available. The OSD imposes additional requirements as well, such as requiring that the license be technologically neutral and requiring that others be allowed to create derivative works.

The OSI has recognized that people will, for various reasons, want to create new open source licenses. Therefore, they have created a process to vet proposed licenses for compliance with the OSD. Licenses that meet their approval have greater credibility in the FOSS community for having been certified. The approval process has two stages. At the first stage, the proposed license is discussed on the official license discussion mailing list. True to the founding principles of the movement, anyone who has an opinion on a proposed license can contribute. License authors are encouraged to work with the list participants to incorporate feedback. After the list participants have achieved consensus on the proposed license, the process moves to the second stage. At this point, the board of the OSI, which is made up of luminaries in the FOSS community, considers the license and makes the final determination on certification. The board’s decision is strongly influenced by the consensus of the license discussion list.

Despite the popularity of the GPL, there have been many complaints about it over the years. Many people believe that the GPL is longer and more complex than it needs to be. Some say that the license is too ambiguous, and many say that it is too wordy. As Linus Torvalds, the creator of Linux, said, “In many ways, my only gripe with the GPL has been how many words it seems to need to say something very simple.” Even the Free Software Foundation has stated that they “enthusiastically invite those who believe that the GPL can protect freedom just as well in fewer words to join our comment process and show us how this can be done.”

Professor Robert Gomulkiewicz of the University of Washington School of Law decided to respond to that challenge by creating a new license. His goal for this license, called the Simple Public License (SimPL), was to create a license that the average open-source programmer could easily read and understand without the help of a lawyer.[3] The SimPL is designed to implement the key features of the GPL, including the copyleft, without sacrificing readability. By way of rough comparison, the SimPL has fewer than 400 words, while the GPL has more than 2400 words.

We submitted the SimPL to the OSI in mid-March and are currently working with the participants on the OSI license discussion mailing list to better match the terms in the GPL and to ensure that the SimPL fully complies with the OSD. The list participants have offered a number of well-reasoned comments that have led to a significantly improved license. We continue to work on the license and are very hopeful that the process will go well and culminate in approval by the OSI.

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  • [*] James Sfekas is a student at the University of Washington School of Law. He has been assisting Professor Robert Gomulkiewicz in his preparation of the SimPL.
  • [1] Available at
  • [2] Available at
  • [3] Available at

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