I am using the MIT License for a particular piece of code. Now, this license has a big disclaimer in all-caps:


I've seen a normally capitalised disclaimer on the zlib license (notice that it is above the license text), and even software with no disclaimer at all (which implies, i take it, that there is indeed a guarantee?), but i'd like some sourced advice by a trusted party. I just haven't found any.

GNU's License notice for other files comes with this disclaimer:

This file is offered as-is, without any warranty.

Short and simple.

My question therefore: Are there any trusted sources indicating that a short rather than long, and a normally spelled rather than capitalised disclaimer (or even one or the other) are safely usable in all of the jurisdictions I should be concerned with?

For the purposes of this question, the software is released in the European Union, should it make any difference.

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    Check with a lawyer, as I'm sure the people who wrote the GPL/BSD did :)
    – Tim Post
    Dec 27 '10 at 16:09
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    @Tim I'm hoping someone else has done that already, and I'm looking for their verdict. Not to be misunderstood: I'm not looking for someone's opinion, but trustworthy evidence. Dec 27 '10 at 16:14
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    I got curious enough about the caps to ask. See my answer.
    – Tim Post
    Dec 27 '10 at 16:30

IANAL, but one works with me. So, I asked. The result:

  • The caps allow you to say 'no way could they have missed the disclaimer, it is hardly fine print!' This is important in a license or EULA that non-lawyers must read and accept.

  • There is a difference between 'express' and 'implied'. Some areas have laws that allow people to 'imply' a warranty, even though one was not explicitly offered, unless you make certain specifications.

He suggested not making any changes to existing licenses, as that basically creates a whole new (and likely weaker) license. License proliferation is a problem. Bad license proliferation is a bigger problem.

The license is designed to protect you, and given this brave new era of endless litigation, caps and run on sentences that very few people read to begin with are a small price to pay :)

This is one of the biggest reasons why V2/V3 of the (L|A)GPL specifically say that altering the license is prohibited.

People sue, every day .. for damages that common sense should have averted. For instance "How did I know the coffee was hot? I wouldn't have spilled it on my lap if it was labeled as so .."

You really should take care not to weaken a 'shield' that prevents gold diggers from bothering you.

  • The other biggest reason that the GPL licenses prohibit alteration, is that some jerk could otherwise take the GPL, insert some restriction like "you may not remove the link to my site" (flowplayer, i'm looking at you!), call it the GPL, and (1) make the initials "GPL" meaningless, and (2) mislead the FSF fans into incorporating the product without reading yet another copy of "the GPL" (which in reality places restrictions on them over and above the GPL, but that they'll never realize til they get sued).
    – cHao
    Nov 9 '11 at 21:30
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    The "common sense should have averted... How did I know the coffee was hot?" is a gross mischaracterization of the Stella Liebeck case, which has been distorted in the media since 1992. And Liebeck was not a "gold digger", she offered to settle for only her $10,500 medical damages for skin-grafting needed for 6% third-degree burns, but McDonald's tried to lowball that with $800. There certainly are gold diggers and dishonest frivolous plaintiffs, but Lieback wasn't one. You should edit this stuff out of your answer.
    – smci
    Jul 30 '20 at 13:49

The all-caps disclaimer in the MIT license is more or less a copy-paste from the legal language found in commercial shrink-wrap licenses, where the spelling out of "no warranties" is required to be more legally precise than it needs to be for free software. Since open-source licenses do exist that do not have this legal verbiage, I assume that the short form is probably OK.

As with all things legal, if you are really concerned about it, you should consult a lawyer that specializes in software licensing law.


The disclaimer is there to protect you as the original author. Otherwise there might be implied warranties by law you would need to fulfill when passing along the software work.

As you can imagine in technical systems, this can be complex and that is why you really want to exclude the warranty. This is also what entry-level or more advanced literature on the topic suggests.

As society increasingly relies on software to perform critical functions in everything from manufacturing to life support systems, the risk that an error in a software program will lead to economic loss, property damage, or personal injury increases. Prudent software developers will be cognizant of these risks and will take steps to minimize their exposure to this type of liability. Determining how far a software developer should go in this effort requires balancing the degree of exposure to software product liability against the adverse impact, if any, of the steps required to limit this exposure on the software vendor's ability to market and sell its software.

(from: IV. Conclusion - Software Product Liability: Understanding And Minimizing The Risks (By Lawrence B. Levy and Suzanne Y. Bell) )

As you are probably giving your software away under very liberal free software terms, you better consult a lawyer before changing an established and widely accepted license text (yes that can do a difference and if I read @Tim Posts Lawyers feedback right, this is also what his lawyer meant. You can find that as well within comments/publications by other lawyers also especially about free software licenses).

However, this disclaimer is no carte-blanche for everything. In Germany for example you couldn't reduce liability by such a warranty disclaimer easily by just adding it below the terms.

Because full warranty for a software as required by law would have put too many liabilities on the original author - who actually most often doesn't earn a cent - this has been better clarified for Free Software as there are now some sentences in German law to make this more clear (and to allow warranty disclaiming to a certain degree). This didn't put the world as we knew it before topside-down, but just saying that things aren't as easy as they seem on first sight and in a critical area it's perhaps better to stay with a critical mass of users of the same terms to effectively fight back in case it's necessary.

You can find these kind of implications also in the terms of the GPL 3 which is a modern license with international use in mind:

Sections 15. is a Disclaimer of Warranty and 16. is a Limitation of Liability:

17. Interpretation of Sections 15 and 16.

If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, reviewing courts shall apply local law that most closely approximates an absolute waiver of all civil liability in connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee.

(from: GNU General Public License - Version 3, 29 June 2007 )

This is only possible if you stick to the accepted practices which includes not to change the accepted Free Software license texts including the warranty disclaimers beneath them for (more or less) personal reason.

However, the MIT license text you relate to in your question does not have a requirement to retain the warranty disclaimer.

Which probably can make sense because in some cases of contracting a licensing of the software or a work based on it might require you to remove this really broad disclaimer and negotiate more precise terms here.

However it's perhaps not a good idea to remove it because of that, the OSI FAQ has the topic of different warranty as well (not specifically, see below) and the wording suggests a warranty sold separately which probably makes indeed much more sense:

Some companies may sell you a warranty separately, for a fee, but that is not part of the open source license, it's just your private contract with that company.

(from: Can I restrict how people use an Open Source licensed program? - OSI FAQ )

So changing and removing it does not seem to be permitted and it does not look like you would loose any rights of re-use, however what you actually do here is to destroy the text and offer warranty for too many users as you are actually willing to care about.

Further text-analysis by others might not easily identify the original license this was obtained from adding one more step/point to follow over while clarifying the license of a work (for a third-party using that work). Then other users might be puzzled and what not. Therefore keep this transparent is the best suggestion I can give.

And do that for a reason. Just formatting purposes because it does not please your taste? Well, it's a free world so you can do whatever you want, but this is also for giving something to others so keep in mind that this can make others live a bit more complicated. Just decide what is important for you and which risks you are willing to take.

And if you have legal questions, well, better ask somebody who is able to answer those to you in a legally binding manner (not saying that lawyers will do always, but chances are higher you will be more educated later on from the legal viewpoint :)). But I guess you know the deal.


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