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2026

Archived version 1 of 2. This is how the model read before it was corrected. It is shown read only. The current version is here.

The zlib libpng License

Also known as Libpng, The Zlib/Libpng License, ZLIB.

Commercial use
allowed
Share alike
not required
Attribution
required (keep the copyright and license notices)
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Canonical URI https://dalicc.net/licenselibrary/TheZlibLibpngLicense

Permissions

  • Charge distribution fee from the text Charging a fee for the act of providing a copy of the work to someone else.
  • Commercial use from the text Using the work to generate income, directly or indirectly, for example by selling it or by using it in advertising.
  • Derivative works from the text Distributing an adaptation of the work and making it available to the public.
  • Derive from the text Creating a new work from the work, such as a translation, adaptation or arrangement of it or of a part of it.

    Duties

    • Modification notice from the text Marking a changed work as changed, saying how it differs from the original and keeping earlier notices of change.
    • Notice from the text Notice: keeping the license and copyright notices with every copy.
    • Rename from the text Giving a modified or derived work a name that tells it apart from the original.
  • Display from the text Showing the work to the public without making a copy the viewer keeps.
  • Distribute from the text Providing copies of the work to the public or to anyone else.

    Duties

    • Notice from the text Notice: keeping the license and copyright notices with every copy.
  • Modified works from the text Distributing a modified version of the work that does not amount to a new, derivative work.
  • Modify from the text Altering the work, for example by updating it, without creating a new work; an alteration that creates a new work is Derive.

    Duties

    • Modification notice from the text Marking a changed work as changed, saying how it differs from the original and keeping earlier notices of change.
    • Notice from the text Notice: keeping the license and copyright notices with every copy.
    • Rename from the text Giving a modified or derived work a name that tells it apart from the original.
  • Present from the text Performing the work in public, including by broadcast or other communication to the public.
  • Reproduce from the text Making copies of the work in any form.

Prohibitions

This license states no prohibitions.

License-wide duties

This license states no duties that apply to the work as a whole.

Info

Target asset types
Software
Region / jurisdiction
Worldwide
Validity
Perpetual
Source
http://opensource.org/licenses/Zlib
Legal code
http://opensource.org/licenses/Zlib
This description is published under
https://dalicc.net/licenselibrary/CC-BY-4.0
Publisher
N.N.
SPDX identifier
ZLIB (provisional, the record declares none)
DALICC identifier
TheZlibLibpngLicense

This record is published under CC BY 4.0. Credit it as: DALICC License Library, DALICC - Verein zur Förderung der Rechtssicherheit in der Datenbewirtschaftung, https://dalicc.net, CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). The license it describes belongs to its publisher.

History

This license model has 2 versions. Version 2 is the one served today; every earlier version keeps its own address, so a conclusion drawn from one of them can still be checked against it.

  1. Version 2 current2026-09-24 Giray Havur

    The content review of 2026-09-15 added 1 clause text and 1 identification detail and recorded the review state. Later changes brought it in line with its family and its text in the verification of 2026-09-15, permitted relicensing with the notice as a duty, corrected it against its text on 2026-09-23, recorded which sentence of the text each statement rests on and named the license the record itself is published under.

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    13 changes

    • added dalicc:WarrantyDisclaimer "This software is provided ‘as-is’, without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software."

      Review finding The opening paragraph is a warranty disclaimer and was not recorded. Added, quoted from the text.

    • added dalicc:reviewStatus dalicc:Reviewed

      Review state Every record records how far it has come in the editorial workflow and when it was last checked against the legal text.

    • added dalicc:reviewedOn "2026-09-15"^^xsd:date

      Review state Every record records how far it has come in the editorial workflow and when it was last checked against the legal text.

    • added spdx:licenseId "Zlib"

      Review finding Added Zlib. Verified rather than taken on trust: cc:legalcode already points at the Open Source Initiative page that the SPDX entry lists under seeAlso, and the fetched text is the same three-restriction license.

    • added dalicc:LiabilityLimitation "In no event will the authors be held liable for any damages arising from the use of this software."

      Manual edit Library conventions 10 and 14: the disclaimer held both sentences of the zlib notice, the second beginning 'In no event will the authors be held liable for any damages arising from the use of this software', and dct:publisher was the placeholder 'N.N.'.

    • changed dalicc:WarrantyDisclaimer "This software is provided ‘as-is’, without any express or implied warranty."

      was dalicc:WarrantyDisclaimer "This software is provided ‘as-is’, without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software."

      Manual edit Library conventions 10 and 14: the disclaimer held both sentences of the zlib notice, the second beginning 'In no event will the authors be held liable for any damages arising from the use of this software', and dct:publisher was the placeholder 'N.N.'.

    • removed dct:publisher "N.N."

      Manual edit Library conventions 10 and 14: the disclaimer held both sentences of the zlib notice, the second beginning 'In no event will the authors be held liable for any damages arising from the use of this software', and dct:publisher was the placeholder 'N.N.'.

    • added permission dalicc:ChangeLicense with duties [dalicc:compliantLicense]

      Manual edit Permit relicensing on permissive licences; the notice clause is a duty, not a bar. Library convention 15: a licence that asks for no reciprocity and no source code asks only that the notice travels with the copy, which is a duty on the acts it governs and not a bar on putting the copy under other terms. dalicc:ChangeLicense is therefore a permission here, and the prohibition the record carried before is removed. The text reads: "Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions: 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software." The permission carries the dalicc:compliantLicense duty, as Apache-2.0 does, because the notice has to survive the relicensing.

    • removed dct:alternative "Libpng"

      Manual edit The alternative name "Libpng" is dropped. The SPDX license list gives that identifier to a different text, the libpng notice, which the library now holds as the record Libpng, so a lookup for the name reached the wrong licence.

    • changed permission dalicc:ChangeLicense with duties [dalicc:compliantLicense]

      was permission dalicc:ChangeLicense with duties [dalicc:compliantLicense]

      Manual edit The statement is marked as a library convention, family rule 15: Permissive records permit relicensing: the text does not state it in as many words. Its duty dalicc:compliantLicense is marked as a library convention, family rule 15: Permissive records permit relicensing.

    • changed permission odrl:derive with duties [cc:Notice, dalicc:modificationNotice, dalicc:rename]

      was permission odrl:derive with duties [cc:Notice, dalicc:modificationNotice, dalicc:rename]

      Manual edit Its duty dalicc:modificationNotice quotes "Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software."

    • changed permission odrl:modify with duties [cc:Notice, dalicc:modificationNotice, dalicc:rename]

      was permission odrl:modify with duties [cc:Notice, dalicc:modificationNotice, dalicc:rename]

      Manual edit Its duty dalicc:modificationNotice quotes "Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software."

    • added dct:license <https://creativecommons.org/licenses/by/4.0/>

      Manual edit Every record is published under CC BY 4.0. cc:license names the record DALICC keeps of that licence; dct:license now names it by the address Creative Commons publishes it at, so that a consumer matching the canonical IRI finds it.

  2. Version 1

    The version this model had before the content review of 2026-09-15.

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Every change names the reason behind it: a finding of the content review, one of its library-wide decisions, the metadata that review wrote onto every record, or a hand edit. None of it is legal advice.

Nothing on this page is legal advice. What a license means is decided by its text; ask a legal advisor before you rely on it.