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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.

PNG Reference Library version 2

Also known as PNG Reference Library License version 2, libpng-2.0.

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/libpng-2.0

Permissions

  • Change license from the text Replacing the license of the work, or of an adaptation, with another license, or changing its terms.

    Duties

    • Use a compliant license from the text Choosing a replacement license that stays compliant with the terms of the original license.
  • 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.

Clauses

Warranty disclaimer

The software is supplied "as is", without warranty of any kind, express or implied, including, without limitation, the warranties of merchantability, fitness for a particular purpose, title, and non-infringement.

Limitation of liability

In no event shall the Copyright owners, or anyone distributing the software, be liable for any damages or other liability, whether in contract, tort or otherwise, arising from, out of, or in connection with the software, or the use or other dealings in the software, even if advised of the possibility of such damage.

Additional clauses

1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated, but is not required.

Info

Target asset types
Software
Region / jurisdiction
Worldwide
Validity
Perpetual
Source
https://spdx.org/licenses/libpng-2.0.html
Legal code
http://www.libpng.org/pub/png/src/libpng-LICENSE.txt
This description is published under
https://dalicc.net/licenselibrary/CC-BY-4.0
SPDX identifier
libpng-2.0 on the SPDX license list
DALICC identifier
libpng-2.0

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 changes since version 1 recorded which sentence of the text each statement rests on and named the license the record itself is published under.

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    2 changes

    • 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.

    • 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

    Created from the license text on 2026-09-22 (Permissive variants).

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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.