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2026

X11 License

Also known as MIT X11, X11, X11 License.

Commercial use
allowed
Share alike
not required
Attribution
required (keep the copyright and license notices)
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Write this as a license text (needs an account) DALICC reads the model above and writes what it permits, requires and prohibits in plain English. Without an account, the Text download above writes the model out from the vocabulary.

Canonical URI https://dalicc.net/licenselibrary/X11

Permissions

  • Change license by library convention Library convention: family rule 15: Permissive records permit relicensing. Replacing the license of the work, or of an adaptation, with another license, or changing its terms.

    Duties

    • Use a compliant license by library convention Library convention: family rule 15: Permissive records permit relicensing. 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

    • Attribution from the text Giving credit to the copyright holders or authors of the work, in the form the licensor asks for.
    • Notice from the text Notice: keeping the license and copyright notices with every copy.
  • 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

    • Attribution from the text Giving credit to the copyright holders or authors of the work, in the form the licensor asks for.
    • Notice from the text Notice: keeping the license and copyright notices with every copy.
  • Grant use from the text Granting third parties the right to use the work.
  • 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

    • Attribution from the text Giving credit to the copyright holders or authors of the work, in the form the licensor asks for.
    • Notice from the text Notice: keeping the license and copyright notices with every copy.
  • 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.
  • Sublicense from the text Granting a third party rights in the work under a license of the licensee's own, rather than passing on the original license.

Prohibitions

  • Promote from the text Not permitted: Promote. The text says: "Except as contained in this notice, the name of the X Consortium shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization from the X Consortium." Using the name or trademarks of the licensor or of contributors to endorse or promote a product.

License-wide duties

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

What applies by default

The statements above are the library's reading of this license: each is marked with the sentence it rests on, or as a library convention where the text is not explicit. The statements below are the ones the DALICC reasoner supplies for acts the license says nothing about, from the default rules of the dependency graph it reasons with. Each one names the legal source it rests on. None of it is in the record.

No default rule of that graph reaches this license: it speaks about every act the rules are about.

Clauses

Warranty disclaimer

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.

Limitation of liability

IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Additional clauses

Except as contained in this notice, the name of the X Consortium shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization from the X Consortium.

Info

Target asset types
Software
Region / jurisdiction
Worldwide
Validity
Perpetual
Source
https://spdx.org/licenses/X11.html
Legal code
https://spdx.org/licenses/X11.html
This description is published under
Creative Commons Attribution 4.0 International
Publisher
X Consortium
SPDX identifier
X11 on the SPDX license list
DALICC identifier
X11

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.

Use this license

Everything below is generated from this record. Replace the example address with the address of your own work.

JSON sidecar 

{
  "license-uri": "https://dalicc.net/licenselibrary/X11",
  "license-title": "X11 License",
  "spdx-id": "X11",
  "attribution": "Copyright (c) [year] [copyright holder]",
  "asset": null,
  "generated-by": "DALICC"
}

RDF, Turtle 

@prefix cc: <http://creativecommons.org/ns#> .

<https://example.org/my-work>
    cc:license <https://dalicc.net/licenselibrary/X11> .

RDF, JSON-LD 

{
  "@context": {
    "cc": "http://creativecommons.org/ns#"
  },
  "@id": "https://example.org/my-work",
  "cc:license": {
    "@id": "https://dalicc.net/licenselibrary/X11"
  }
}

HTML attribution 

<p>This work is licensed under <a href="https://dalicc.net/licenselibrary/X11" rel="license">X11 License</a>.</p>

This license asks for attribution, so the credit line is part of it.

Badge DALICC badge for X11 License

Markdown 

[![License: X11 License](https://dalicc.net/license-library/X11/badge.svg)](https://dalicc.net/license-library/X11)

HTML 

<a href="https://dalicc.net/license-library/X11"><img src="https://dalicc.net/license-library/X11/badge.svg" alt="License: X11 License"></a>

Review

Written from the license text by
Giray Havur
Written on
2026-09-22
Second review
not yet done
Record changed since this review
yes (version 2, 2026-09-24)
Findings
12 recorded, 9 applied to the record, 0 proposed

Models the licence the X Consortium wrote for the X Window System. The grant and the notice condition are the MIT ones word for word; what the X text adds is a clause keeping the consortium's name out of advertising and promotion, and a sentence noting the trademark. The record is MIT plus a dalicc:promote prohibition.

12 findings

  • info Rubric 1 spdx:licenseId applied

    File name, record identifier, SPDX identifier and IRI local name are all X11. SPDX keeps X11 and MIT as separate identifiers although the grant is the same, because of the name clause, and so does this library.

  • info Rubric 2 odrl:target applied

    One odrl:AssetCollection of dct:type dcmitype:Software, following MIT.

  • major Rubric 3 odrl:permission applied

    The grant reads "Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so". The record permits reproduce, distribute, modify, derive, display, present, grantUse, sublicense, commercial use, derivative works, modified works and the distribution fee.

  • major Rubric 3 odrl:permission applied

    dalicc:ChangeLicense is permitted with the dalicc:compliantLicense duty, as on MIT.

  • major Rubric 4 odrl:prohibition applied

    dalicc:promote is prohibited for "Except as contained in this notice, the name of the X Consortium shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization from the X Consortium". This is the one statement that separates the record from MIT.

  • major Rubric 5 odrl:duty applied

    cc:Attribution and cc:Notice hang off odrl:distribute, odrl:modify and odrl:derive for "The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software".

  • minor Rubric 6 dalicc:WarrantyDisclaimer applied

    The disclaimer paragraph holds the warranty sentence and the liability sentence and is split into the two predicates, as on MIT-0.

  • info Rubric 6 dalicc:additionalClauses applied

    The trademark sentence, "X Window System is a trademark of X Consortium, Inc.", is quoted. dalicc:trademarkNotice is not used: the sentence states a fact about a mark and puts no duty on the licensee, and the duty term is for a licence that asks the licensee to carry such a notice forward.

  • info Rubric 7 cc:jurisdiction applied

    The text names no legal system and sets no term, so cc:jurisdiction is dalicc:worldwide and dalicc:validityType is dalicc:perpetual.

  • info Rubric 8 dalicc:additionalClauses none

    No clause of this text needs a term the vocabulary does not have.

  • info Rubric 9 record none

    The consistency check of app.services.composer against the dependency graph dg_default returned an empty conflict list.

  • info Rubric 10 record none

    Read against licensedata/licenses/MIT.ttl the difference is one prohibition, dalicc:promote, and two quoted clauses. The permission set is the MIT set with dalicc:sublicense stated as well, which MIT-0 also does for the same wording of the grant.

Report an issue The review record as JSON The review checks the model against the license text. It is not legal advice.

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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    3 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.

    • changed prohibition dalicc:promote

      was prohibition dalicc:promote

      Manual edit The statement now quotes the sentence of the licence text it rests on: "Except as contained in this notice, the name of the X Consortium shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization from the X Consortium."

    • 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.