Open Source License Conditions

By David D. Rodrigues

If you are considering releasing your proprietary software under an open source license or if you plan on incorporating source code which is governed by an open source license into your proprietary software, you need to fully understand the terms of the license which governs the source code. Open-source software is not synonymous with “free software.” Although the term “open source software” is not strictly defined, it signifies that a particular piece of software is provided under a type of license that generally satisfies a series of elements.

Open-source software licenses are not all alike. Each particular open source license can vary in terms from another license, and each can include its own unique obligations and restrictions. The terms of a particular license should be reviewed in the context of what may best suit your ultimate goal for your software. For example, assume that you just finished authoring a piece of software and want to distribute it under an open-source license—you may want a license which ensures that the original author (i.e., you) always receives attribution rights in derivative works created from your software, limits how third parties can redistribute your software, and other terms that you may view as desirable. On the other hand, assume that you are someone who may use open-source software to incorporate into your own project. Because you may have several selections to choose from, you may want to select software which is governed by a license which is permissive and imposes minimal terms, allows you to use the open-source code liberally, and is least burdensome to you, your business, and your proprietary software. Even so, you need to abide by the license terms. In the context of these varying positions and goals, certain open-source licenses may be unduly burdensome, while others may fit your professional/business goals.

Regardless of the open source license used, it’s important to remember that an open source license creates “enforceable copyright conditions” and that “copyright holders who engage in open source licensing have the right to control the modification and distribution of copyrighted material.” Jacobsen v. Katzer. As such, regardless of whether the license imposes strict terms or is permissive, the terms incorporated into the open-source software are enforceable copyright conditions, assuming that the software itself is subject to copyright protection.

There are numerous open source licenses available, all of which have differing terms. Examples of these licenses include the Affero General Public License, the BSD License, the Creative Commons license, and the GNU General Public License. These licenses have various version numbers, so it is important to determine which version of the license applies to software you may be using. If you want to license your source code under any of these licenses, or want to use source code which is subject to an open source license, be sure to adhere to the license’s terms to remain in compliance with the original license.

When reviewing the terms of an open-source license, keep in mind the following points when reviewing an open-source license, while understanding how it may impact your use of the open-source code subject to the license:

1. Is the distribution of the source code or object code limited in any way?

If you anticipate distributing a derivative work from the original license work, you should determine whether the license allows you to do so. Generally, open-source licenses are permissive regarding the distribution of the source code and derivative works of the original source code. That said, although a license may appear to be permissive, conditions for the distribution of the source code can still apply and can vary from license to license. For example, the Apache License 2.0 permits a licensee to “distribute copies of the Work or Derivative Works thereof in any medium, with or without modifications,” provided that you meet the enumerated conditions specified in the license. Other licenses, such as the BSD 3 License, require redistributions of the source code to include the copyright notice, the list of conditions and disclaimer provided in the original licensed work (other conditions apply if distributing the object code). Again, be sure to understand any terms surrounding redistribution of the open-source code and how it would impact your ability to distribute your own source-code derived from the license software. Also, if you anticipate any commercial use of the open-source software, be sure that the license does not restrict any commercial use of the licensed software.

2. Does the open source license allow for the modification of the source code by a licensee?

If you intend to create a derivative work from the open source code, then the license must permit modification of the original source code. Otherwise, you can only use the source code as provided by the license. Most open source licenses permit modification of the source code. For example, the GNU GPL v3 permits a licensee to “convey a work based on the [open source software], or the modifications to produce it from the [open source software],” provided that the licensee meets the enumerated conditions specified in the license. Depending on how you anticipate using the open source code, it is important to understand the conditions associated with the modification of the open source code.

3. Does the license grant you any additional intellectual property rights in the open source code?

Remember that open source licenses generally license copyright rights associated with the source code. However, a process executed by open source code may also be subject to patent protection, or the name used to identify the open source software may be subject to trademark protection. Although some open-source licenses do not address issues concerning patent or trademark rights, there are open source licenses that specifically grant or restrict any patent or trademark rights associated with open source software. For example, the Apache License 2.0 grants the licensee a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable patent license regarding any patent rights related to the licensed open-source code. However, that same license specifically advises that the license “does not grant permission to use the trade names, trademarks, service marks, or product names of the Licensor…” As such, you should be aware whether the license conveys any other intellectual property rights and, if so, what additional rights or restrictions you may have under the license.

4. Is the license a “copyleft” license?

Generally, copyleft licenses provide that any person who receives a copy of the work has permission to reproduce, adapt, or distribute it. However, these licenses also require that any resulting copy or derivative work of that software must be bound by the same licensing agreement. As such, if you plan to develop proprietary software from source code distributed from a copyleft license, or plan to place your source code under an open source license, be sure that you understand that your proprietary software and any rights associated with it will be bound by that same copyleft license. This is especially important when considering any proprietary rights associated with your software (including patent rights) and whether you want those rights to be available to licensees of your software by means of an open-source license.

Ultimately, it is important that you understand the terms governing open-source software before you decide to incorporate or create derivative works from open source software as it can ultimately determine how you can use and distribute that software.  Failing to understand the scope or terms of an open-source license can be detrimental. Before using open source software, or if considering licensing your proprietary software under an open source license, you or your counsel should carefully review the provisions of the open-source license, understand how it can affect your software (including software which incorporates the licensed software or is developed from it), and, if you will use the licensed software, ensure that you remain in compliance with the terms of the license. As with any copyright license, failure to comply with the terms of an open source license, such as attribution and modification, transparency requirements, or use outside the scope of the license can result in a finding of copyright infringement, or infringement of any other intellectual property rights that the license may convey (e.g., patent rights). Therefore, although open-source software may be freely available, keep in mind that open-source software is not “free,” but is licensed to you under specific conditions which you as a licensee are bound to.