Since our own Alaukik asked me to put a few scripts under GPL-License I wondered if I am doing it correctly. The points that concern me are:

  1. Do I have to include the whole license with my project or is a comment like # Copyright by John Doe, 2011 Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php legally sufficient?
  2. Do I have to include my real name or is an e-Mail or other alias legally waterproof?
  3. Is the year important? I would guess 'yes' as copyrights expire in most countries after a certain period. What happens if I don't?
  4. Should I use GPL over MIT? I tend towards MIT as it is more permissive and I don't care whether my scripts are used in closed source software.


There is a very good page on 'How to use GNU licenses for your own software'. The gnu website also makes suggestons on how to aply the licenses to your project (™Flimm). That covers a lot for the GPL.

Bottom line - license choice:
If you want to support free software, don't use too free a license. Disallowing proprietary use gives free software an edge over proprietary programs. In theory with some licenses re-usage of your code must credit your original. But re-usage is difficult to proof and some corporations might just not credit you. However, if you do want to spread your software as wide as possible, i.e you don't care about proprietary products using your software, then use MIT or LGPL. If in doubt use the more restrictive license and add a line, saying you may consider permitting uses outside of the license terms on a by-case basis. This way commercial users with a project worthy of your work have a chance.

Bottom line - copyright dispute:
Include as much information as you dare to make proving it's really your brainchild easier. Have a lawsuit over the ownership in the back of your head. Poor man's copyright is mailing a printed copy of your source to your home address. If the envelope is unbroken, the postmark is valid evidence at court and provides a date and a verified address. An e-mail instead of your full name to identify you should be okay and sufficient proof but: Better safe, than sorry.

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    I think you should better stick with GPL or LGPL, as it sounds solid and associates with fanatics, and generally easy to get lawer help about. I have heard somewhere that having to copy licence text again and again with every package upsets low-space gadget developers. – Barafu Albino Jun 1 '11 at 12:14
  • You might be right. For GPL I read about precedent cases in most countries. Don't know how the situation is with MIT – con-f-use Jun 1 '11 at 12:17
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    i think you mean 'used in proprietary software' by 'commercially recycled' since gpl allows commercial redistribution of the software . – Lincity Jun 1 '11 at 12:35
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    I'm not sure there would be precedent from MIT-related legal cases because it's that permissive. You couldn't sue somebody because (as long as they didn't say you endorsed their product), you have no say in what they do with your code. – Oli Jun 1 '11 at 12:36
  • Correction. Anyone may sue any person for any reason at any time, whatsoever, frivolous or not. Licenses like Expat (ambiguously referenced as MIT in OP) do not preclude this fact, though they do obviate it during legal proceedings. – Josh Habdas Nov 5 '19 at 7:14

I should prefix this with: I am not a copyright lawyer. If you're really concerned about something, contact one. People at the FSF might be able to help you.

You should include the full text of the license. Even if you just stick it in a LICENSE file at the root of the project. I don't think anything immediately bad would happen if you didn't but in the long term (which copyright is), not having a solid reference to your license could be a bad thing.

Being explicit doesn't cost very much time.

Edit: actually the WARRANTY section might be worth including for your protection, whichever license you choose. I have no evidence to say that not including it implies a warranty, but again, be safe, not sorry.


A copyright notice (© <date> <name>) isn't legally required in most places anymore but not including it doesn't help anyone. You'd have a harder time proving you owned copyright and it would be a lot harder for people who want to license it under different terms. I would definitely put it in there... But I guess this isn't really an issue with BSD/MIT -style licenses.

As for using a handle or nick, in other medias people have been using pseudonames for centuries. If it came to a legal suit, you'd need to be able to prove you are that person so obviously this might make it a little harder but it's not insurmountable.

If you're going MIT, you have so little legal recourse that these issues will probably never apply to you.

The year in the copyright notice isn't essential but if you wanted to sue somebody in several decades time, you'd have to prove when it was created. Which might be hard. A fixed notice helps you and costs nothing but a few seconds.

We should be clear here.

  • GPL allows commercial redistribution but the source code of the whole thing must be available (with changes) to anyone who purchases a copy of it .
  • LGPL is good for software libraries. These can be included in proprietary projects without needing to redistribute the whole source. The only time source distribution needs to happen is if they edit your code and even then, they only have to release their changes to it.
  • MIT code can be relicensed freely. Somebody could take your code, verbatim, and re-release it under GPL, proprietary licenses, etc.

"GPL vs MIT" is an eternal battle. Go with whatever you're actually happiest with, not what is most convenient. If you're not happy for potentially evil people to take your code and use it for potentially evil or lucrative purposes, use something where you have some recourse like GPL. If you really don't care and you're not using any GPL'd code yourself, a more liberal license like MIT would be fine.

Remember virally-open-source licenses aren't just good for you, they ensure that your work, however it's adapted and re-released is free for everybody under the same terms. Even if you're dumping the code with no interest in maintaining it, GPL gives it a better hope of remaining free.

There's no need to rush it these decisions either but you have to think of the worst possible cases to really know if you're making the right decision. Once it's released under one of these licenses, that's it, it's done.

  • Okay, thanks alot. That answered my question for the most part. Point 2 (aliases etc.) still requires an answer. To include the whole license in a simple single file script would be overkill so I won't do that - there a reference has to suffice. For small script files anyone could write I really see no reason not to release them under MIT. – con-f-use Jun 1 '11 at 12:47
  • Omitting any data that traditionally goes in a copyright notice hurts your ability to prove you own the copyright. The more you put in there, the easier it gets. If you put the year, proper name and contact email address, you should have no problem confirming your identity. But omitting it wouldn't make thing too hard for you. I'd say if you're going with [L]GPL: put as much as you can. If you're going MIT, do whatever you like ;) – Oli Jun 1 '11 at 12:50
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    The MIT License states: "The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software." So the way I understand it a fictive 'Evil Corp.' still had at least to say: 'this and that part is copyrighted by John Doe' if they used any of my code. Of course in a binary only distrubution it would be hard to tell if they used my code... – con-f-use Jun 1 '11 at 13:26
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    "take your code and use it for potentially evil or lucrative purposes, use something where you have some recourse like GPL" - unless somebody equals "evil" and "close source" GPL offers little limitation against use of code for evil. – reducing activity Jun 1 '16 at 14:19

At the end of the GPLv2 license, there's a guide on how to apply the license terms to your project. The FSF put a lot of effort into writing that document and making it as legally valid as possible, so I'd follow their advice.

If you decide to use the GPL license, please make sure that you include the 'version 2 or later' clause. This will save you headaches later, and make GPLv2 projects compatible with GPLv3 and vice-versa.

Like Oli said, you don't legally need to use your real name or your email in the header of a file to keep your copyright rights, but it's highly recommended to save you and other people from headaches later on.

Deciding between the GPL license and the MIT license is both an ethical and strategic decision, and there are many arguments in favour of either one.


Do I have to include the whole license with my project or is a comment [...] legally sufficient?

No need to get clever. Just follow the guidelines. You should generally include the GPL license header with each of the scripts you're adding. Add or confirm the full text of the GPL exists in a file called COPYING and is included in the source. If you're trying to include GPL scripts in a broader Expat licensed work you cannot as the compatability does not work in that direction.

Do I have to include my real name or is an e-Mail or other alias legally waterproof?

Nothing is water-tight where law is concerned. If your name is Satoshi Nakamoto probably use something else to more uniquely identify yourself. It can be a moniker, pen name or even a Bitcoin address.

Is the year important? I would guess 'yes' as copyrights expire in most countries after a certain period. What happens if I don't?

Yes, though without it it may take others longer to reasonably determine the year of copyright expiration.

Should I use GPL over MIT?

Yes, since that's what you stated you were asked to do. In a more general sense the permissive nature of Expat may come back to bite you.

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