Duration of a license granted without specific bound
<p>Recently, a <code>node</code> software developer asked that his packages be un-published from an index of software packages called "npm" when the developer was threatened with trademark infringement.  The package un-publication caused a cascade of functionality problems with software dependent on one of these packages.</p>

<p>The developer had not explicitly revoked their license, this question is related but on a more general focus.  What if the core open-source packages we depend on so critically were suddenly revoked and re-published with different terms, or none at all?  Can we create a derivative work based on previously published terms?  If we've already created a derivative work bound by the same license as the original author, are we infringing if they revoke the original license?</p>

<p>The specific <a href="https://opensource.org/licenses" rel="nofollow">wording of the most popular licenses</a> do not explicitly grant for any particular term.  Does that mean it's only valid until explicitly revoked, or perhaps it's valid perpetually/until copyright expires?</p>

<p>Possibly relevant cases:</p>

<ul>
<li>TV Globo v. Brazil Up-Date Weekly</li>
<li>Rano v. Sipa Press</li>
<li>Walthal v. Rusk</li>
</ul>

<p>This seems to be a little-considered problem with open-source licensing. The <a href="https://opensource.org/licenses/Apache-2.0" rel="nofollow">Apache license</a> says "grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license", which is what you want. The <a href="https://opensource.org/licenses/MIT" rel="nofollow">MIT license</a> says nothing about the durability of the license. <a href="http://www.ilaw.com.au/public/licencearticle.html" rel="nofollow">This article</a> has some analysis of the problem of such software licenses, noting that there probably isn't a contract (lack of consideration, lack of acceptance), but you still have the limitations implied by copyright. That implies that they could revoke permission to make further copies of the software, but it would not require you to delete or stop using legally-acquired copies. (But "cannot modify" in the context of source code probably functionally means "cannot use").</p>

<p>His analysis is that if you don't have a contract, then <em>even if</em> you say that the license is irrevocable, you can unilaterally change the terms of the license. <a href="http://cases.justia.com/federal/district-courts/texas/txedce/4:2009cv00218/116142/219/0.pdf?ts=1411579008" rel="nofollow">Nearstar, Inc. v. Waggoner</a> observes that "A nonexclusive license may be irrevocable if supported by consideration": I am not aware of any case where someone attempted to revoke an Apache-style "irrevocable" license, and until that comes up, you just have conflicting opinions where <a href="https://wiki.creativecommons.org/index.php/Frequently_Asked_Questions#What_happens_if_the_author_decides_to_revoke_the_CC_license_to_material_I_am_using.3F" rel="nofollow">one side just asserts their position</a>. Some protection may be afforded in the US by <a href="https://en.wikipedia.org/wiki/Uniform_Computer_Information_Transactions_Act" rel="nofollow">the Uniform Computer Information Transactions Act</a>, if it has been enacted in your state, which it probably hasn't.</p>

<p>It is not clear to me what the law says about a person's obligation to inform others of a change of permission, so if I openly grant permission to copy ad infinitum, that does not create a duty for users to check my web page on an hourly basis thereafter to make sure that I have not taken back my permission. </p>

<p>I want to post an answer to my own question in order to supplement the existing answer(s).</p>

<p>Some licenses (GPLv3, e.g.) are explicitly irrevocable.</p>

<p>This article, "<a href="http://scholarship.law.uc.edu/cgi/viewcontent.cgi?article=1146&amp;context=fac_pubs" rel="nofollow">Shrinking the Commons: Termination of Copyright Licenses and Transfers for the Benefit of the Public</a>", indicates in its abstract:</p>

<blockquote>
  <p>If GPL or Creative Commons-type licenses are subject to later termination by authors ... users of such works must confront the possibility that the licenses may be revoked in the [future] ... the better course would be for Congress to enact new legislation expressly authorizing authors to make a nonwaiveable, irrevocable dedication of their works, in whole or in part to the use and benefit of the public-a possibility that the Patent Act expressly recognizes, but the Copyright Act presently does not.</p>
</blockquote>

<p>I'd dispute Malcom's claim that there's no consideration for software licenses (reference given in other answer).  There's multiple factors that could be seen as quid-pro-quo:</p>

<ul>
<li>quality improvements of the software under license (via subsequent bug reports, patches)</li>
<li>career development of the licensor</li>
</ul>

<p>...that said, there is rarely a manifestation of acceptance of a contract in any real sense.</p>

<p>I'm going to expand on the existing answers.</p>

<p>The Apache license has the following clause: (italics mine)</p>

<blockquote>
  <p><strong>2. Grant of copyright license.</strong> Subject to the terms and conditions of this License, each Contributor hereby grants to You a <em>perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable</em> copyright license to reproduce, prepare Derivative Works of, publicly display, publicly perform, sublicense, and distribute the Work and such Derivative Works in Source or Object form.</p>
</blockquote>

<p>That's just fancy words for saying, you can use this work however, wherever, whatever, whenever, forever, for any reason, I won't charge you royalties or stuff. And I won't take this license away from you unless you break the license terms.</p>

<p>So then, what's the issue?</p>

<p>Since the work's license is <em>irrevocable</em> and <em>perpetual</em>, you will still be entitled to the license rights with <em>your copy</em> of the work. Whatever the original author does with their copy, will not affect what you can do with yours.</p>

<p>Now, the question boils down to... <em>Was it appropriate for the author to take down all copies?</em></p>

<p>Threatening with trademark infringement, or any infringement (be it copyright, patent, or trademark) is serious. If this happened...</p>

<p>The author has the right, and likely the responsibility  to remove and destroy all copies of the software. That software is improperly licensed; by using it, you are infringing on the original person's right as well. If I used the software, I would be in trademark infringement.</p>

<p>Generally, the open source world doesn't share these concerns. Most modern open source licenses have these clauses, specifically those that are advanced and impose many restrictions, or freedoms. The MIT license is a simple license, that imposes and doesn't touch base with many areas - this is to keep it compatible with the vast array of other licenses that are out there.</p>

<p>There's a lot of discussion surrounding this on <a href="//opensource.stackexchange.com" rel="nofollow">Open Source Stack Exchange</a>. You may want to visit :)</p>

united-states copyright