Difference between revisions of "Intellectual Property, Copyright, and related rights"

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==See also==
==See also (copyright)==
* http://en.wikipedia.org/wiki/Copyright
* http://en.wikipedia.org/wiki/Copyright

Revision as of 18:59, 9 May 2022

This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)
These are primarily notes
It won't be complete in any sense.
It exists to contain fragments of useful information.

BIG RED TEXT HELLO: This is not legal advice, or necessarily correct. Do not make legal decisions based on this.

I'm just someone on the internet, trying honestly to figure this out, ideally simplifying it a bit for general consumption, but any of this is at best a introductory read before diving into the real choices/implications/legalese.


IP's practical concepts

Intellectual Property includes (but is not limited to):

Copyrights are exclusive rights on an original work/expression, primarily the rights to sell, display in public, reproduce, make derivative works.

Meant largely to and stimulate and protect investment in a creative process, by rewarding that creator.

Violated copyright is often about profiting from someone else's work, and proven by showing whose work it was.

Trademarks give their owner exclusive rights to use a particular symbol or phrase to identify a particular product or manufacturer.

For companies this is mainly about brand investment, for consumers often about quality, specifically not being misled by imitations.

(America also uses Service Mark to signify that we're talking about a trademark used for a service, rather than goods)

Violated trademarks are often about misleading people about brands, and proven by showing people are confused in their purchases.

Patents give their owner exclusive rights to use a particular invention, i.e. a new idea and its direct implementations. (In theory this is about inventions regardless of precise implementation - though in some fields that distinction is vaguer than you'ld think)

Meant to stimulate investment in research process, by rewarding the time and money invested in development by giving the inventor a share for a limited amount of time.

Violated patents are about profiting from someone else's costly research (...well, that's the intent, not always the practice, or legal measure used in court)

Trade dress[1] can covers some ground the last three do not.

It deals with recognition of a product, or even its packaging. Which can be very fuzzy, and arguably is protection of brand and marketing.

So in intent, it's arguably closest to trademarks.

It is e.g. meant to stop counterfeiters from making things that look almost indistinguishable except from e.g. a slightly different logo that lets them "well technically..." their way out of it being a trademark violation.

Fake handbags do that, for example. For another example, when tablets were still newish, Apple sued Samsung when their tablet started physically resembling the iPad a little too much - which would not be a patent violation due to different tech, or trademark because they did clearly mark it with their own brand.


This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)


This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)

Basic copyright

Copyright is what gives you rights on an item to

  • reproduce
  • sell
  • make derivative works
  • display the copyrighted work in public

It also lets you alter each of these rights on a work, e.g. authorizing others to do some or all of those things.

Basically, it protects the cost and effort put into original works, from being exploited by others not putting in that effort.

Copyright makes it worth it to interest nontrivial time to make something original.

Copyright does not need to be registered anywhere.

Copyrighting is automatic on anything tangible you create, as soon as something is painted, written, or whatnot. (...'tangibly' is a historic thing. Digital forms are a little less clear-cut, though laws are slowly catching up.)

If you create a work by yourself, you have exclusive rights - meaning no one else can use it without your permission.

For-hire work has its own logic, but broadly, "whatever you put on paper".

A copyright notice is not necessary for copyright to apply.

...anymore, in most places. For example, in the US it was required until since 1989, and Night of the Living Dead (from 1968) forgot to, and was considered public domain becase of it

Even whre it is not required, this notice...

  • is an easy signal that you care about the copyright
  • signals when you have allowances freeer than nothing, as is becoming more usual (consider CC licenses)
  • marks the owner of the work
...which is basically saying "..but I didn't know it was protected".
which in most cases is weak and in the end won't stick legally. It's just that if there is a notice, they more clearly have no case
  • A copyright notice often consists of:
    • the copyright symbol
    • the date of creation (for software often a range, the active years of development)
    • the name of the copyright holder
    • "all rights reserved" (used to be required, now optional)


  • Copyright applies to public use, not private use.
roughly because there is very little to exploit privately.
  • Work made for hire comes roughly in two forms:
In practice, if something falls directly within the scope of a job you're hired for, your employer gets the copyright
...worded in a way that doesn't let your employer steal your hobby projects, and to be fair about people going into business for themselves, creating a new distinct thing in the same field.
commissioned work is the creator's and not the commissioner's, unless you explicitly sign the rights over
It is in the interest of both parties (and fairly typical) to have a contract with specific mention of transfer
for artists, to specify details that may be challenged later, including attributions of style and originals
for commissioners to get rights, limited or not, in the first place

  • Granting these rights has to be done in writing - just saying it's fine is not enough
  • Individual (or even full) rights can be granted on a case-to-case basis, or a blanket basis.
You can also (effectively) sell copyright along with an item
  • When copyright holders are individuals, they're often not not very picky about granting them, particularly for individual and non-commercial use.
When holders figure something may be sold, then you often deal in conditions and money (quite expectable when holders are are businesses)
  • You could make any agreement that holds up legally. A work can be sold, and/or rights granted. For example, a work...
...can be sold with all rights (e.g. original works)
...can be sold / loaned with some rights restricted (consider music, DVDs, etc.)
...can be due to royalty fees when publicly displayed/reproduced (consider music)
...can have specific uses granted, e.g. allowing it to be put on shirts
...can have uses granted for a limited area time, e.g. reprint rights in america for two year, internet post rights for one year, or whatever. Also relevant for 'limited edition' things. Usually only worth doing on valuable IPs

  • "royalty-free" does not mean "copyright free"
Royalty-free is a copyright agreement that says "we won't charge you for using this publically" - and often with specific conditions, e.g. type of use (where, how)
the agreement itself
may still be for money - e.g. there are royalty-free stock image sites, often resellers with their own pricing model
or not - there is royalty free music online [2] without charge (often from the artists themselves)


Some practicalities

International copyright

International copyright for a large part it does what you expect, but it is not a given, and copyright specifics differ per country.

Countries basically apply their own copyright law to foreign copyrighted material, due to how the agreements on copyright developed over time.

Legally, a large chunk of the details that matter internationally seem to come from:

Copyright length

Copyright runs out.

When they do, the works pass into the public domain (note that the term Public Domain is a US-centric one).

Because the length is settled, there is usually a date before which almost everything is public domain (either because there was no copyright or because it has expired).

For example ~1922 in the US.

Internationally, most books before 1945, and every book before 1787.

More recently, it depends on:

  • when it was made,
  • what type of work it is (different lengths apply)
  • whether the copyright was extended (if possible)
  • possible other specifics
  • possible legal changes (e.g. in the US and other countries, copyright length has been repeatedly increased, from ~30 to ~100 years)

Copyright assignment

Copyright and the internet


If someone infringes, you can of course ask them to stop doing so.

If you expect a person just liked the work (more than being a legal expert), and you can often easily come to some agreement or other.

In case of real and willful abuse, the best idea is often to consult a copyright lawyer to weigh your options.

In practice is is often true that suing will usually cost more money than you'll get in return (and sometimes it means bad publicity), but it is likely a useful way of stopping the infringing.

Uncopyrightable things

This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)

Under certain law, there are a number of things that can't be copyrighted.

The rules and lists vary, so but check local the details.

In the US: (most of this is copy-pasted from copyright.gov)

  • Titles, names, short phrases, and slogans; familiar, everyday symbols or designs; variations of typographic ornamentation, lettering, coloring; listings of ingredients or contents.
note that some of this is trademark stuff instead.
  • Works that have not been fixed in tangible form of expression (for example, choreographic works that have not been notated or recorded, or improvisational speeches or performances that have not been written or recorded)
  • Works consisting entirely of information that is common property, containing no original authorship (for example: standard calendars, height and weight charts, tape measures, lists or tables taken from public documents or other common sources)
  • Ideas, procedures, methods, systems, processes, concepts, principles, discoveries, or devices, as distinguished from a description, explanation, or illustration

Particularly in the first and last case, but also in general: note that patents and trademarks are different things and may still apply.

On crediting

Say you add "I do not own this. All rights belong to the creator, name and link." and possibly some more legalese.

And the real question is whether it affects the creator's ability to sell the thing - and keep making such things at all.

So copying plus a credit is still infringing.

You're just being nice about it.

(nicer than, say freebooters, e.g. copying popular videos to their own channel to get ad revenue. Even if you do it without ads, you are still taking away from their ad revenue)

Practically, it now depends on what the artist/owner wants.

If it's the odd shared images on social sites do as much good as harm to them, they may not care to make a fuss.

If it does have a real influence (including when a large company does this, a clearer case of being explotative), then they probably will.

This is also part of why "I gave them exposure" is not a legal argument - or often true at all.

It's also why removing copyrighted material later doesn't nullify the effect it had earlier.

Fair use

Fair use describes exceptions to copyright, cases where a use would normally be infringement, but for specific reasons is not.

...also the area of many myths, so also more than a few legal cases.

The most useful angle to focus is whether it serves a different purpose, an actual change in what it means for consumers. In legalese, whether it is transformative.

Transformativity is not the only factor, but it's the one you would pick in introductions like this, because it tends to imply the other ones as well.

Remember that copyright intends to protects a creator's investment in a creative process.

If something is not transformative, it will easily play in the market that the copyright holder created with the work, so easily tak the same audience and have them view and pay for that derivative instead of the original - at the cost of the person who created that market in the first place.

The clearest case would be digital piracy/freebooting - plain copies of the thing.

But there are many other types of content piggybacking that you can find now.

So if we value creation of new things of quality, there really do need to be rules about this.

If transformative, then chances are good it won't affect the author's market - of the original creation.

Most uses in research, reviews, parodies are considered transformative, because they don't serve the same purpose.

Examples and myths

"You're making money, it can't be fair use" / "I'm not monetizing, so it's fair use"

Monetization has no bearing on whether the use is fair use.

You can absolutely make money off actually-fair-use things.

Yes, in many cases, it's harder to do. And since each thing must be transformative enough, doing this consistently well to make money you can live off is probably so much more effort that most people will not even want to do this as a career, but may absolutely consider it for hobby or a specific video essay they always wanted to make.

Money being made is certainly relevant, e.g. to how quickly and how thoroughly your case will be scrutinized.

If getting paid for it makes people find other arguments for it to be fair use are questionable, it will matter to a legal decision that the total support is 'not much'.

Even then, that legal decision would not be made because you're making money, but because you're making money from the same market/audience, because stealing market based on close copies is one of the things copyright is designed to protect.

It may also matter to you in the practical sense of people constantly trying to find fault.

"If I add 'this is fair use', 'no infringement intended', and/or pointing out the copyright owners, that makes it safe"

In general, this does absolutely nothing legally.

None of that changes any of the just-mentioned points.

The owners may be somewhat less likely to sue you, but for other reasons.

(Note it's still possible for something to be fair use regardless' of this statement)

Educational uses, use in research, use in news reporting is fair use

It in indeed easy, in each of these fields, for its used to be implicitly transformative, but that's not because of what the field is, but because of what it typically does'.

Say, if you're studying a thing in depth, you may show much of the thing, but most of the content will be that study.

A video fragment in the news mostly just shows the context we're talking about.

At the same time, it's absolutely possible, within each of those fields, to violate copyright.

It doesn't happen very quickly, but is very easy if you are trying.

"Using short fragments makes it fair use"

It's not the fact that they are short, it's, well, several things. Often mostly that most uses that only need a short a short fragment tend not to play in the same market.

And it's not the length of that fragment, it's more the fact that they are saying "thing is good example, now here's a discussion, which is the actual content here".

This is a good part of why the just-mentioned educational, research, and news reporting are okay, and also part of why critical review, response videos, video essays, and such usually are as well.

It also relates to why parodies are quickly fair use, because its nature is the criticism of the actual content, distancing it from the content itself. But they are a topic of their own.

Sure, in practice people will probably check how of that content there is, and compare it to the amount of shown content.

Show one or two scenes, then talk about it for a dozen minutes? Probably fine.

Show a dozen minutes, then remark on one word? Probably not.

"If changed more than 10% it's fair use / not infringement"

There is no magic percentage, or timespan, or whatnot. While contents matter, use matters more.

Maybe ask a random person on the street. Do they say thing A is similar in purpose to thing B? Then you're probably on dangerous ground.

"If I change the lyrics, it's fair use"

That depends, and music is a more complex case in general.

In many places the composition and recording has separate protection, plus sampling is its own thing that can get you into trouble even on an otherwise original creation. Or people that licensed that original creation because they didn't yet realize it was an issue.

This is why covers are not simple, and have actually gotten more complex these days.

That said, play a silly version with different lyrics, particularly in criticism, and you may be fine.

If you're just making it sorta-kinda-different but mainly clear reference, not so much.

And, while the risk is yours, you probably don't want probably-stuffy lawyers making the decision for you.

Case in point, Weird Al, probably the most prolific parody artist since the eighties, asks for permission (and apparently licences(verify)) all of his songs.

He may not need to, but it's less worry than the legal nonsense.

Apparently he does have a dozen songs where, while the law would probably be on his side, he just won't release because the artist didn't approve. Presumably it's a mix of principle and 'not worth the potential legal bother'.

"If I talk over it it's fine"

Can be, but it depends.

Say, youtube response videos will often talk over the thing they're reviewing. Or maybe show it muted. Or maybe show a short looped thing continously.

The point is largely that when you're responding most of the time, that's fairly clearly transformative.

Yet if you show an entire movie, you'ld need to do serious amounts of yapping for it to not maybe amount to a public showing. And people probably wouldn't watch the result.

Case in point, MST3K licensed most of the movies (and presumably found a few with expired copyright?(verify)). Not because it wasn't transformative - you can argue that it often was, and maybe they would've usually been fine. Yet they made a decision that it's not worth the risk and cost of lawsuits, which probably doesn't outweigh getting that license.

(RiffTrax was an audio-only thing because that removed all worry, providing the same fun with only a little syncing for you to do)

copyright claims

spurious copyright claims


Public domain and similar


CC0 is arguably more useful than saying it's public domain, in that it's a fallback license for places where PD isn't legally possible.




The Do What The Fuck You Want To Public License is basically equivalent to releasing into public domain


The Unlicense


Unsorted (copyright)

See also (copyright)

(Chain) License comparison

Note: Most licenses here are software licenses.

Most are also chain agreements, where copying/using implicitly agrees to holding up the same terms, which can form a copy-and-agree chain.

This is different from basic copyright, in which you only deal with the copyright holder, which is often the single original creator (or distributor) of the content.

Potentially confusing points


This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)

Free software licenses "free the recipient from any legal barriers which would inhibit their freedom to run, study, modify, or redistribute the software - both modified and unmodified." (source: wikipedia)

This deals deals with liberty of use (also 'free as in speech' , libre, similar terms) in the wider sense of the term. People like Stallman have pointed out that there are some distinct freedoms (can be seen as levels) that free software aims to make free:

  • The freedom to run the program for any purpose.
  • The freedom to study how the program works, and change it to make it do what you wish
  • The freedom to redistribute copies so you can help your neighbor.
  • The freedom to improve the program, and release your improvements to the public, so that the community can benefit.

Open Source Software, OSS, deals with the availability of source code. Open source implies that you can use the software, and look at its source.

And does not mean you are free to redistribute modifications, so isn't always free software.

The difference between free and open software can be subtle in its definitions, but can be pretty clear in its implications.

Free Open Source Software, FOSS (also sometimes FLOSS or F/OSS) is both of the above, and is probably what you were thinking of if you're a geeky idealist: You can get at the code, you can change it, and code can be easily shared back - and may have to be (if released in any form).


  • we often say 'open source' meaning 'free open source'
  • ...or close. There is e.g. dual-licensed stuff that work like "you have most freedoms for personal use, but commercial use has more details".
  • neither freeness nor openness refers to pricing to the end user ('free as in beer', gratis).
As long as the applicable licenses do not specifically restrict it, free and open source may well be sold.
...though you often won't get people to pay for much more than distribution costs, because the code is available
...yet there are sensible, profitable business models, often when it's sensible for your customers. Often meaning selling support services, which some linux distributions have successfully done.

See also:

Source license, non-source licenses

Licenses may be explicitly specific to certain content types.

Many licenses are source-code licenses, because they are written with terminology meant for source code. Which is necessary due to the way source gets combined.

Recently, copyleft licenses specific to text, metadata, video media, audio media, datasets, and more have appeared.

Copyright and copyleft, 'Chain agreement', 'viral license'

Basic copyright is implicit and default is most of the world. You make something, it's copyrighted, as implied by the laws that apply to everyone in a country.

In contrast, copyright agreements are between people - usually to extend a specific right, and applies just to the two(-ish) people involved.

Businesses usually deal with intellectual property via basic (absolute-style) copyright: there is a single content owner (often its creator, or at least their employees, or anything for which the rights were signed over) you can seek them out and sign some agreement, which tends to mean "you can use this copy"-style copyright agreement.

There are a good number of agreements that (via the wording of their license) imply a chain agreement because the legalese roughly says that:

if you take any version of the content,
you use it under the terms (rights, obligations) it was released under,
where those terms include clauses that mean the license preserves itself (partially or fully)

In other words, the same license applies for the person before you, you, the person after you. This wording means it makes legal sense without a central owner.

Copyleft tends to refer to that self-preserving construction when it is geared to offer freedom to use, study, copy, and modify a work, while distribution (of original or, more relevantly, derived versions).

Commonly via the chain agreement way, but there is variation how. And some distinction between strong and weak copyleft:

Strong copyleft perpetuates all its restrictions. The GPL is a common example because it is easily explained: If you pick up something GPLed, you may only release it under the same terms - no more, no less. In other words, no matter how much GPLed content evolves, adapts and gets adopted, it will stay GPLed.

Weak copyleft means licenses where there are situations where fewer restrictions apply.

Permissive licenses, such as the MIT, BSD, Apache, and others, do not require you to distribute changes, and so allow you to close the source, where the only obligation is to mention that you did.

They could be called non-copy left free software licenses


  • library licenses are often a mix.
Take the LGPL, it basically has a "you can use it as a functional unit without restrictions, and the license doesn't affect code outside the library -- but if you change the library itself you have to give back" sort of attitude.

  • GPL is strongly copylefted, a nature which can be seen as both a strong and a weak point.
Strong point in that it's a very simple way to keep the code in the community, which is good for the code itself.
Critics call it a viral license (or even toxic):
once source becomes GPLed, it can't really become licensed under something else
existing GPLed content is very hard to multi-license
...legally entirely possible, but it's usually prohibitively annoying to do - because it means you need to find all past contributors, and get them all to agree.
GPL also puts a lot of force on code you want to use alongside - it basically has to become GPLed as well.
This occasionally means that GPLed software cannot be adopted into certain projects, because it already had code that is either proprietary, or also commonly, under a different license that cannot combine with the GPL -- which is what the term notes 'GPL compatible' is about.
(This is one reason to consider using the LGPL if you can)

There is an argument that historically, GPL was a very useful thing for open source to become a thing in a largely-proprietary market - that these days the same sternness is not useful, and there are more business models where more permissive licenses make equal sense - and lead to more collaboration and cross-pollination.

This is a philosophical debate about what exactly it is that you want to flourish in the long run.

'Substantial portion'

Various licenses state that they apply when the software/document are used in full, alternation, or use of a 'substantial portion' .

This is inherently fuzzy.

Sometimes intentionally - it allows people to copy habits and good structuring ideas, while not allow them to copy-paste the entire project.

Derivative work


Multi-licensing refers to giving a choice of more than one license to use.

Multi-licensing (often just two, i.e. dual-licensing) is not directly about license compatibility. You can multi-license using various incompatible licenses, because it is a "choose one of the following" situation, and the next person only agrees with one at a time .

When one of the two is open source or free license and another isn't, this doesn't exactly make make things easier, and may mean the software takes two different paths over time. However, there are some situations and business models in which this makes sense.

To take a real-world example, the Qt library can be used in two ways:

  • under the paid-for QPL, which allows you to use Qt in proprietary programs without having to release anything, or alternatively
  • under the GPL

Free software projects use it under GPL terms, and the core of the Qt project thrives from that. In addition, you can choose to use it in proprietary code (without having to open anything up) and have to pay for that ability. (And you could develop a variant of Qt, but you probably won't as you can only use it yourself, and there's value in keeping it compatible with newer developments of Qt)

In many situations, dual licensing has proven a bit of an anti-pattern, because it doesn't really give you or your customers anything, and it does still make your life harder.

License compatibility

This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)

When combining two different pieces of software into a derivative work, both licenses have something to say.

"Derivative work" is a whole another can of words: What's a derivative thing, and what's just talking to each other, was clearer in the time of monolithic executables, and vaguer now that everything is much more modular.

But let's talk about the clearer cases of taking two parts and smashing them together into a useful single product that you want to release.

These licenses only have things to say when you distribute a combination - mainly because of the logic behind the copyright law this is all duct taped onto.

...so no, there are no legalities to whatever tinkering you do in your cellar as an end-user. But you should still care about it if you ever want someone else to using your nice tinkered thing.

Legal basics of combination

So what these licenses have to say usually applies because most licenses have a "same license for derivative work" clause.

When both do this, the combination is effectively dual-licensed: Both licenses apply at the same time. And you can't have a legally self-contradictory combination. So some combinations simply are not legally valid to distribute.

Some licenses aren't picky. For example, in the permissive MIT license the same-license is largely so that the author attribution lives on. It says little else.

So while the GPL has more to say, most relevantly "must become no more restrictive," it matches with MIT's points, so the combination checks out.

On the other hand, most other licenses do have something more specific to say. Certainly any proprietary one, but even the now-rare 4-clause variant of the otherwise very permissive BSD license is legally incompatible with the GPL because one cause is "Advertisements mentioning this software must acknowledge its origin/contributors". And even though I'm sure the people who wrote the GPL like the idea, it's additional restriction, so a legal incompatibility with GPL.

So that line in the GPL turns out to be a pain. This is why it's the most common example in license compatibility :)

So what's the license on a combination?

Can you combine with proprietary licenses?

Unsorted (compatibility)

When do requirements apply?

Many requirements apply at the point you release, (re)sell or re-license the software (in binary and/or source form(verify)).

They generally do not apply to personal or hobby use unless that is explicitly stated (and there are legal limits to what may be limited) -- which, note, is also the case for copyrighted materials(verify).

Issues in combining software and licenses

This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)

Source code licenses

Commonly used licenses

See lists like https://www.blackducksoftware.com/top-open-source-licenses

Explanation of Summarizing one-liners

"Must distribute modified source"

This comes from a mindset central to open source: "if you improve it, the benefits are for all - and not at at the cost of money or restrictions". Avoids a lot of double work and wheel reinvention.

Note that technically, this requirement doesn't force use of the same license on the distributed source, but in practice it often does, to avoid fuzzy legalities (and possible abuse).

In practice there are variations of how this applies. Consider for example the the difference between the GPL and LGPL. While the GPL virally forces everyhing open, the LGPL allows for sectioning into libraries, and having each have its own set of implications. Specifically, if you simply use another's LGPL library it has no implications on your source around it. Only if you make changes to the library (or heavily integrate it) you have to distribute.

In BSD / X / style licenses Apache, redistributing modifications is purely optional. It's considered nice and good style and such, of course.

This usually applies when the result is distributed (released, and also often applies when internally distributed within an organisation). In that case, you can only demand the source when software with this restriction has been released, but not before then, or when someone is using for personal use.

Any use or library use → Same license

...means no distinction is made between 'you improve our code' or 'you use our code unchanged for a feature'.

For example, if you use a library to open an obscure sound or picture format but that library forces your grand music player/photo editing application to a particular license, or two such licenses contradict, you just can't use it.

LGPL is a variation of the GPL that essentially puts a library you use on its own legal terms. You can use it without it virally changing the licensing for your app, changes to the library have to be opened.

More exactly, LGPL says only direct derivatives are forced to the same license. This feels more comfortable to various people, so some prefer it. GNU suggests you use the GPL when possible as close-sourced apps can use these libraries without anything in return.

Maintain Attribution and Disclaimer

Well, just that.

The disclaimer tends to be inherent in the license that oft-used 'use the same license' guarantees.

GNU General Pulic License (GPL)


  • Include license
  • Maintain Attribution and Disclaimer
  • Disclose (distribute) modified source (and any source that uses)
  • Same license for derivative work


  • use commercially
  • modify
  • distribute


  • sublicense


  • "you improve it, you tell us" as a shared-cost continuous development cycle
  • Improvements are necessarily fed back to the community (...on release or sale)


  • The tiniest use of GPLed source forces everything to be open (see also LGPL)
  • Implicitly incompatible with various others

Applicability to documents?(verify)

See also:

Version 2 and 3

Version 2 is still relatively current.

Version 3 updates 2 mostly in the point that it would extend to hardware (apparently, (verify)) and would have a provision there are no DRM-like systems (apparently, (verify)).

Similar/related to GPL


CeCILL is a GPL-compatible adaptation of the GPL to the French legal system.

There are also two variants:

  • CeCILL-B, which is rather like BSD, X11, MIT licenses
  • CeCILL-C, which is rather like LGPL

IBM Public License (IPL)

A variation of the GPL that:

  • moves liability from contributor to publisher/distributor.
  • terminates the license on patent disputes

Incompatible with (but generally very similar to) the GPL.

Related to, but not to be confused with IBM's Common Public License (CPL).

IBM's Common Public License (CPL)

  • Source license
  • Maintain Attribution and Disclaimer
  • Must Distribute Modified Source
  • Derivative work → Same license
  • Avoids contributors from sneaking in code with patents and then charing for it.
  • Future reviews could affect earlier software (also true for GPL, though(verify))

Affero GPL (AGPL)

This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)

Affero essentially updates GNU GPL's 'when you distribute' to 'when you distribute or use it as a service.'

Affero GPL is based on the observation that GNU GPL forces you to give out your code only really when you sell to users/companies as a product. So if you make alterations, host the thing yourself, and use it to provide services, you don't have to share your modifications.

When your software is SaaS-like to start with, then this is a potential loophole you may want to close.

When not, then it's a bit of a draconian measure, and just makes some things more bothersome (as you must distribute even modifications necessary to get something to work locally, and certainly local extensions).

AGPLv1 is based on GPLv2 -- and incompatible with it (because of the extra clause).

(AGPLv2 is AGPLv1 plus a "AGPLv1 or any later version" note, meant to allow shift to AGPLv3)

AGPLv3 is based on GPLv3, and these two are compatible. (verify)

See also:

Server Side Public License (SSPL)

This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)


BSD-style licenses

BSD licenses (a.k.a. Berkeley licenses)

All vesions:


  • Include license
  • Maintain Attribution and Disclaimer
  • Disclose (distribute) modified source (and any source that uses)
  • Same license for derivative work - to sustain the attribution requirement.


  • (for coders) you can use this code without strong implications
  • (businesswise) this code can be used in proprietary programs you sell, requiring only attribution


  • (program/communitywise) vampirism is easy - anyone can use without doing someting in return, although this only really happens outside the (F)OSS communities.
The common examples are Microsoft's IP network stack being directly adapted from BSD's, and Apple's OS X which is strongly based in FreeBSD and mostly closed-source. No sharing, but you can argue both are positive results to end users.

For the case of binary distributions, these licenses will require copyright notices to be placed in the documentation.

Note that there are different versions of this license, and that similar (ISC, MIT) and derived (OpenBSD, NetBSD) licenses are often functionally equivalent to one of them. (See also: [4])

See also:

4-clause, "Original BSD License", "BSD license with advertising clause"

The original BSD license had four clauses. NetBSD still uses it. The clauses roughly require that:

  • Code (re)distributions must retain the copyright notice, the clauses, and the mentioned disclaimer
  • Binary (re)distributions must retain the copyright notice, the clauses, and all disclaimers
  • Advertisements mentioning this software must acknowledge its origin/contributors (what exactly to mention is stated in each specific license)
  • Names of copyright holders nor contributors may not be used in endorsements of (this/derived) software without permission.

Not GPL compatible because of the clause about advertisements.

The advertisement clause was initially intended for BSD. Once used elsewhere, though, this means licenses were floating about with arbitrary mentions to the University of California, and many licenses with programmers' own names, which causes larger projects (e.g. and merging such software) to require any ads to mention dozens of names.

3-clause, "Modified BSD License"

The "3-clause", "Modified BSD license" removes the third clause from the 4-clause version, making it:

  • Code (re)distributions must retain the copyright notice, the clauses, and the mentioned disclaimer
  • Binary (re)distributions must retain the copyright notice, the clauses, and all disclaimers
  • Names of copyright holders nor contributors may not be used in endorsements of (this/derived) software without permission.


2-clause, "Simplified BSD License"

FreeBSD and others use just the first two rules, i.e.:

  • Code (re)distributions must retain the copyright notice, the clauses, and the mentioned disclaimer
  • Binary (re)distributions must retain the copyright notice, the clauses, and all disclaimers

This is generally the assumed version when people say 'BSD license'.


MIT license / X11 license

  • Maintain Attribution and Disclaimer
  • Must Distribute Modified Source
  • "Same license for derivative work" (which implies only attribution) (verify)

Since the MIT license does not prohibit the use of the copyright holder's name in promotion, it's basically equivalent to the 2-clause variation of the BSD license

Note: When people say 'MIT license', they usually mean the license originally drafted for X11, probably the most significant license to come out of MIT, though of course not the only one used within MIT.

See also:

Apache licenses (ASL)

This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)
  • Maintain Attribution, Disclaimer
  • Must Distribute Modified Source
  • "Same license for derivative work" (verify)
apparently same license for unmodified, choice for modified?(verify)

A permissive license similar to BSD and MIT style licenses, in that use is free of most restrictions and modifications may be kept secret and sold if one so chooses.

The main differences are additions in ASL:

  • ASL is more more verbose (and legally explicit) about its intent
  • ASL2 adds some more explicit protective detail related to patents
"This License does not grant permission to use the trade names, trademarks, service marks, or product names of the Licensor"
"If You institute patent litigation against any entity ... then any patent licenses granted to You under this License for that Work shall terminate as of the date such litigation is filed."


  • Apache License 1 was GPL compatible (by mostly just being a rewritten BSD license), but
  • Apache License 2
    • became incomptible with GPLv2 (and GPLv1) because of the patent details - but this may be preferable to you
    • ...but seems compatible with GPLv3, in that Apache code can be used in GPL3 works. (verify)

See also:

Academic Free License (AFL)

  • Source license
  • Maintain Attribution and Disclaimer
  • Must Distribute Modified Source

Meant as a clarifying succession to Apache, MIT, BSD, and UoI/NCSA.

However, AFL-1.2 and AFL-2.1 are not GPL compatible. AFL-3.0 may be GPL compatible.


This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)

Meant as a clarified version of the BSD/MIT licenses

Apparently GPL-compatible.

Python Software Foundation license

This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)
  • Source license
  • Maintain Attribution and Disclaimer
  • Must Distribute Modified Source

BSD-style - doesn't require source to stay open, but license must stay intact.


Note that an earlier version, the Python license, was not GPL-compatible (because of some mention of the laws of the State of Virginia) - though the name 'Python license' can also be used to refer to the newer version.

See also:

GNU Lesser/Library Public License (LGPL)

  • Fairly specific to source
  • Maintain Attribution and Disclaimer
  • Must Distribute Modified Source (but not code that only uses)

LGPL is something like 'GPL when you change, BSD-like when you use.'

You have to publicise alterations to the library, but generally this just improves the library quality (may sometimes create a flurry of use and improvement) and rarely forces you to expose something you didn't want to.


  • Code can used in a (larger) project without having to open the entire project now or later


  • Allows legal reverse engineering (but so do most others)
  • LGPL-licensed software can be used in proprietary software. This is a purist view, noting this gives proprietary development an advantage over free software

In a semi-open world, LGPL (or one of the licenses like it) is a fairly good choice of both making your code useful for most everyone and making it low-implication for the most people.

A critical, pro-FOSS-and-anti-proprietary stance would note that you can be giving a proprietary project an edge by doing this since you can both use the library easily. The FSF takes this stance and suggests you use the GPL.

See also:

Open Source License (OSL)

  • Source license
  • Maintain Attribution and Disclaimer
  • Must Distribute Modified Source

(to check)

Not GPL-compatible.


Common Development and Distribution License (CDDL)

From Sun (can be seen as Sun Public License version 2; SPL was basically a revision of the Mozilla Public License).

Allows proprietary software in open source whole, apparently based on the idea that as an OS you couldn't do without closed-source drivers.



Artistic License

Python Software Foundation License ('Python License')

Licenses mostly specific to single projects

Often Application or Project based, and interesting pretty much for that specific case as they originated in specific needs, though are sometimes useful in lightly adapted form

Nethack General Public License

X.Net License

Eiffel Forum License

Mozilla Public License (MPL)

Qt Public License (QPL)

Python license

zlib/libpng license

Apache Software License

Jabber Open Source License (JOSL)

Netscale Public License (NPL)

Apple Public Source License (APSL)

Eclipse Public License



General / content / non-source licenses

Copyright free, public domain

Copyright free means no copyright applies, through action (explicitly given up) or inaction (expired) or whatnot.

(Note that non-copyright legalities still apply, such as publishing with trademarks you don't own)

You can pretty much use the work however you want.

Not even preserving the original author's name is required, though this is often considered good style.

Public Domain is more or less the same thing, though more specific. It is a US-specific concept, exists as something of an addendum to US copyright law, and the concept neither appears in every nation's laws, is not necessarily legally equivalent where it does, and seems to vary even within the US.

Things can enter the public domain / become free of copyright

  • via an outdated (not renewed, or not renewable) copyright
example: 1913 version of Webster's dictionary
  • by implication, such as by being released by the US government (a few other countries do this too)
example: the CIA world factbook
  • by explicit release (though this has been challenged, see below)
example: the Moby lexical resources
However, it is questionable whether you can, in all places that have PD, actively release something into the public domain
e.g. US PD law only mentions it as an implication of having been dead for a long time (and having no heirs to lengthen the copyright). (verify)

Note that even if you technically can't release it, this is unlikely to be a problem

The person who released it under Public Domain is very unlikely to care (they released it to PD for a reason),
they probably have a very weak legal claim to retroactively be annoying about it

Still, if true, there is a difference and it is not the handiest thing to use as a license.(verify)

See also:

Do What The Fuck You Want To Public License (WTFPL)

A no-nonsense variant on Public Domain (...without age conditions, question whether you can release something into PD, and such).


Creative Commons (CC)

Creative Commons refers to a set of licenses that allow you to choose the gradation of permissiveness.

The basic CC licenses are the possible combinations of the following requirements:

  • Maintain Attribution (and Disclaimer)
  • All require the original creator to be named
  • Option: Share Alike: derivative work must be shared with same license
  • Option: Non-Commercial: work may not be used for commercial purposes
  • Option: No Derivative Works (only allowed to distribute unaltered copies of the work) OR derivative works allowed (but imply same license)

So there's a a bunch of combinations, like BY, BY-SA, BY-ND, BY-NC, BY-NC-SA, BY-NC-ND

Note that this carries very varied meaning.

Say, BY, BY-SA are 'do whatever, have fun'
Whereas anything with ND means 'you cannot do anything with this'.
Creationwise it's just as controlling as copyright, but you're allowed to post it for free exposure.

CC has since created additional licenses, including:

See also:

GNU Free Documentation License (FDL, GFDL)

The FDL (a.k.a. GFDL) applies to text rather than source, and was created partly because some GPL terms are specific to source and hard to apply to text. The FDL also pays more attention to the more physical nature that documentation, books and such may take.

(Technically, you 'can' use the GPL for general works, but you need to clarify the meaning of some og the GPL's terms, such as 'source code')

The upsides include copylefting needs, and the ability to use other FDL'd content. FDL is used in various open content wikis, including Wikipedia.

One downside is the burden introduced when you distribute more than 100 physical copies: you must include the FDL text and the source form for the content (digitally or physically). This is a problem for some formats, like pamphlets.

One common alternative is a Creative Commons license.

See also:


Gnu Simpler Free Documentation License (GSFDL)

A license, currently (2009) in draft (2006 version), based on the GFDL, apparently created to serve uses that are restricted mostly by Cover Texts and Invariant Sections requirements.

See also:

FreeBSD Documentation License

A permissive license. Rather like the BSD license, but for text.

See also:

Free art license (Licence Art Libre)

This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)

See also:

Apple's Common Documentation License

This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)

Lesser General Public License For Linguistic Resources (LGPLLR)

This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)

Meant to keep data for (computational) linguistics open for use, and keep its derivatives similarly open.

Design Science License (DSL)

A license meant for sharing scientific data, images and such rather than text or source.

Open Publication License (OPL)

May be used in free or non-free form, and has some restrictive options.(verify)).

From the Open Content Project, which now seems to recommend CC.

See also:

Open Content License

Somewhat restrictive, mostly monetary.

Arguably replaced by the Open Publication License.

See also:

Project Gutenberg License

This article/section is a stub — probably a pile of half-sorted notes and is probably a first version, is not well-checked, somay have incorrect bits. (Feel free to ignore, or tell me)

Refers to the overall license applying to Project Gutenberg - which mostly notes that public domain laws differ between countries, and explains copyright details that may apply to some resources -- note that PG has roughly two types of resources:

  • public domain resources
    • which technically come with the non-public-domain Project Gutenberg trademark and license. You either abide by these, or strip any reference to PG from the text (for a fully public domain resource)
    • some may have additional restrictions (verify)
  • copyrighted resources that authors gave to the project (mostly for ease of distribution), which are usually under more specific terms.

The exact details of a resource are explained in a summarizing blurb that comes with the text.

See also:

See also

Lists of licenses with comments:

Just lists:

Other discussions, comparisons and comments: