Gnuplot seems to be one of the rare applications with the level of perfection in rendering graphics (will be glad to know if any competitor exists to this level).

My question is related to the license restrictions of this dependency if I want to use it in my computational applications.

I am not well-versed with license terms and conditions, kindly treat this as a beginner question. I believe softwareengineering.SE is the ideal place to start understanding.

Also, I am not interested in changing the source of gnuplot. I want to distribute the binary along with my software either in commercial or in open-source form.

My main questions are:

  1. The clauses 1--4 talk about patches of the source in case there are any changes. But the way the binaries are to be distributed is unclear. Can I just ship some latest build along with my software without any worry? Should I copy gnuplot's license statements to my license? (exact copy?)

  2. Will the use of gnuplot restrict the choice of licenses that I can use for my software?

The licensing of my software has not been decided yet (could be open source or commercial), but want to know all the restrictions that may come up due to this dependency on gnuplot.

Below is the latest copy of the license of gnuplot

 * Copyright 1986 - 1993, 1998, 2004   Thomas Williams, Colin Kelley
 * Permission to use, copy, and distribute this software and its
 * documentation for any purpose with or without fee is hereby granted,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.
 * Permission to modify the software is granted, but not the right to
 * distribute the complete modified source code.  Modifications are to
 * be distributed as patches to the released version.  Permission to
 * distribute binaries produced by compiling modified sources is granted,
 * provided you
 *   1. distribute the corresponding source modifications from the
 *    released version in the form of a patch file along with the binaries,
 *   2. add special version identification to distinguish your version
 *    in addition to the base release version number,
 *   3. provide your name and address as the primary contact for the
 *    support of your modified version, and
 *   4. retain our contact information in regard to use of the base
 *    software.
 * Permission to distribute the released version of the source code along
 * with corresponding source modifications in the form of a patch file is
 * granted with same provisions 2 through 4 for binary distributions.
 * This software is provided "as is" without express or implied warranty
 * to the extent permitted by applicable law.
  • It seems (not a legal advice obviously) that you should be fine distributing Gnuplot in any way you want. However, if you change the source code of Gnuplot itself, you have to include the original Gnuplot source code and the changes you made to it as patches.
    – Jan
    Nov 22, 2017 at 12:07
  • 1
    The license text is short and pretty understandable, it looks to me it already contains all the information you asked for. So do you have a specific question about it which can be answered better by a softwareengineer than by a lawyer?
    – Doc Brown
    Nov 22, 2017 at 12:58
  • @DocBrown I think the OP is looking for how your statement it looks to me it already contains all the information you asked for maps onto the license. EG Given the OPs requirements and the license text, how do you arrive at your conclusion? (But I am not 100% sure if this is the best forum for that discussion.)
    – Peter M
    Nov 22, 2017 at 13:20
  • @PeterM: the OP asked about the restrictions which the license imposes on his software, and the restrictions are mainly point 1, 2 3 and 4 for binary distribution, and the patch file restriction for source code distribution. So if he did not understand something from that text (which is IMHO written well), he should tell us what. And yes, this site is definitely the wrong place for a discussion.
    – Doc Brown
    Nov 22, 2017 at 13:52
  • 1
    @LovesProbability: IANAL, but when you do not modify the software, apparently the initial paragraph of that license applies and it answers your first question directly, it says crystal clear "yes" and "yes". To your second question: you can IMHO pick any license which does not contradict the gnuplot license, so your license should make sure further copies/distrbutions from your program together with gnuplot contain the license text as well, as required by gnuplot license. But if your fear to get sued, don't trust strangers from the internet, better ask a lawyer.
    – Doc Brown
    Nov 23, 2017 at 6:45

1 Answer 1


The key is that the gnuplot software is not part of your software.

I want to distribute the binary along with my software

Yes, exactly. You will be distributing your own commercial software, and alongside it you will distribute a binary of the gnuplot software. You haven't modified it, so all is well. Anyone wishing to see how the gnuplot in your product works is free to inspect the unmodified gnuplot sources. Just be sure to let your customers know which specific version of gnuplot your binary build process used.

Gnuplot is excellent but it has worthy competitors, including matplotlib.

EDIT: The license offers two cases, the more complex one involving modified gnuplot code, and the simpler one being the path you are following. In the simpler case, the license stipulates "that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation," so be sure to include such notices. The FSF offers some standard advice on how to incorporate such notices.

  • Thanks. But what are the consequences in case someone has included the source code of gnuplot in theirs?? Nov 23, 2017 at 22:58
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    Someone, or you, may freely distribute unmodified gnuplot source code. Similarly, you may freely distribute binaries that come from unmodified source. The license is a program that asks you to simply follow its instructions. "This software" refers to unmodified gnuplot. Do take care to display the copyright and permission notices.
    – J_H
    Nov 23, 2017 at 23:06
  • @JH Thanks, that was a quick reply. "Displaying copyright & permission notices" is a very important point to be taken care of. Do you mind to include in your answer? Does this mean displaying as a part of my own copyright or elsewhere? Nov 24, 2017 at 0:29

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