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2026

Jam License

Also known as Jam, Jam 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/Jam

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.
    • Modification notice from the text Marking a changed work as changed, saying how it differs from the original and keeping earlier notices of change.
  • 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.
  • 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.
    • Modification notice from the text Marking a changed work as changed, saying how it differs from the original and keeping earlier notices of change.
  • 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.

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.

  • Promote by default rule (adopted) Using the name or trademarks of the licensor or of contributors to endorse or promote a product.

    This license says nothing about Promote, and the graph applies this reading in all jurisdictions it covers: it is not permitted unless the license permits it.

    A licence that says nothing about endorsement is read as not allowing it: the licence gives the licensee no right to use the licensor's name or marks in a way that states or implies that the licensor endorses the licensee or its product, while stating truthfully that a work is based on or uses the licensed work is a different act that this rule does not decide. A copyright licence grants rights in the work, and the right to use a name or a trademark is a separate right under trademark law and the protection of names, which a silent copyright licence does not pass on. Combining a licence that is silent about endorsement with one that permits it shows a conflict marked as coming from this rule.

    Basis Trademark and name rights are separate from copyright: Regulation (EU) 2017/1001 article 9 lets the proprietor of an EU trade mark prevent all third parties not having his consent from using the sign in the course of trade, and Directive (EU) 2015/2436 article 10, 15 U.S.C. 1114 and 1125(a), section 12 BGB and section 43 ABGB protect marks and names in the same way. The library's evidence is Creative Commons 4.0 section 2(b)(2): Patent and trademark rights are not licensed under this Public License. A copyright licence that is silent grants no right to use the licensor's name or marks to suggest endorsement (Worldwide)

Clauses

Warranty disclaimer

ALL WARRANTIES ARE HEREBY DISCLAIMED.

Info

Target asset types
Software
Region / jurisdiction
Worldwide
Validity
Perpetual
Source
https://spdx.org/licenses/Jam.html
Legal code
https://www.boost.org/doc/libs/1_35_0/doc/html/jam.html
This description is published under
Creative Commons Attribution 4.0 International
SPDX identifier
Jam on the SPDX license list
DALICC identifier
Jam

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/Jam",
  "license-title": "Jam License",
  "spdx-id": "Jam",
  "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/Jam> .

RDF, JSON-LD 

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

HTML attribution 

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

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

Badge DALICC badge for Jam License

Markdown 

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

HTML 

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

Review

Written from the license text by
Giray Havur
Written on
2026-09-15
Second review
not yet done
Record changed since this review
yes (version 2, 2026-09-24)
Findings
9 recorded, 5 applied to the record, 0 proposed

The record models the Jam license, three lines granting free use and distribution as long as the copyright notice is retained and modifications are clearly marked. It is the one record of this review group with a modification notice duty and without a notice duty for the license text itself.

9 findings

  • major Rubric 3 odrl:permission applied

    The whole grant reads: "License is hereby granted to use this software and distribute it freely, as long as this copyright notice is retained and modifications are clearly marked." Distributing modified copies is assumed by the marking condition, so modify, derive, modified works and derivative works are permitted alongside reproduce, distribute, display, present and commercial use.

  • major Rubric 5 odrl:duty applied

    cc:Attribution on distribute, modify and derive, from the retention of the copyright notice, and dalicc:modificationNotice on modify and derive, from the words modifications are clearly marked. There is no cc:Notice duty: the text asks for the copyright notice, not for the license text. Review decision 8 removed the modification notice from MIT because MIT says nothing about changes; here the text says it in as many words.

  • info Rubric 4 odrl:prohibition none

    No prohibitions. dalicc:ChangeLicense is not prohibited, unlike almost every other record of this review group, because the text requires only the copyright notice to be retained and says nothing about the license travelling with a copy.

  • minor Rubric 6 dalicc:WarrantyDisclaimer applied

    The disclaimer is one line, "ALL WARRANTIES ARE HEREBY DISCLAIMED.", quoted verbatim. There is no liability clause.

  • info Rubric 7 cc:jurisdiction none

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

  • info Rubric 2 odrl:target applied

    One odrl:AssetCollection of dct:type dcmitype:Software, following MIT. The text licenses the software only.

  • info Rubric 9 record none

    The consistency check with the axioms of dg_default returned no conflicts.

  • info Rubric 10 record none

    The license of the Perforce Jam build tool, distributed with Boost. It has no sibling in the library; the closest shape is MIT without the notice condition and with a change-marking duty.

  • major Rubric 3 odrl:permission applied

    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 earlier reading wrote is removed. The text reads: "License is hereby granted to use this software and distribute it freely, as long as this copyright notice is retained and modifications are clearly marked." The permission carries the dalicc:compliantLicense duty, as Apache-2.0 does, because the notice has to survive the relicensing.

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.

    View JSON-LD Turtle RDF/XML

    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 2026-09-15 (Permissive: MIT, ISC and BSD-like).

    View JSON-LD Turtle RDF/XML

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.