GNU Lesser General Public License v2.1 only

Also known as GNU LGPL Version 2.1, GNU Lesser General Public License, GNU Lesser General Public License Version 2.1, LGPL-2.1, LGPL-2.1-only.

Commercial use: allowed
Share alike: 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/LGPL-2.1-only

Permissions

Charge distribution fee from the text
Commercial use from the text
Derivative works from the text
Derive from the text
Duties
- Attribution from the text
- Modification notice from the text
- Notice from the text
- Source code from the text
Display from the text
Distribute from the text
Duties
- Attribution from the text
- Notice from the text
- Patent freedom condition from the text
- Source code from the text
Modified works from the text
Modify from the text
Duties
- Attribution from the text
- Modification notice from the text
- Notice from the text
- Source code from the text
Present from the text
Reproduce from the text

Prohibitions

Change license from the text
Sublicense from the text

License-wide duties

Share alike from the text

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)

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)

Further terms

These are the things the license says about itself beyond the acts it permits, forbids and requires: when it ends, how long there is to put a breach right, which law governs it, and so on. A term that comes from the DALICC vocabulary links to its definition.

Compatible with: GPL-2.0-only
Compatible with: GPL-2.0-or-later
Compatible with: GPL-3.0-only
Compatible with: GPL-3.0-or-later
Or later version option: No
Terminates on breach: Yes

Clauses

Warranty disclaimer

BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE LIBRARY "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE LIBRARY IS WITH YOU. SHOULD THE LIBRARY PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

Limitation of liability

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE LIBRARY AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE LIBRARY (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE LIBRARY TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

Accepting warranty or additional liability

You may charge a fee for the physical act of transferring a copy, and you may at your option offer warranty protection in exchange for a fee.

Additional clauses

As an exception to the Sections above, you may also combine or link a "work that uses the Library" with the Library to produce a work containing portions of the Library, and distribute that work under terms of your choice, provided that the terms permit modification of the work for the customer's own use and reverse engineering for debugging such modifications. You must give prominent notice with each copy of the work that the Library is used in it and that the Library and its use are covered by this License. You must supply a copy of this License. If the work during execution displays copyright notices, you must include the copyright notice for the Library among them, as well as a reference directing the user to the copy of this License. Also, you must do one of these things: a) Accompany the work with the complete corresponding machine-readable source code for the Library including whatever changes were used in the work (which must be distributed under Sections 1 and 2 above); and, if the work is an executable linked with the Library, with the complete machine-readable "work that uses the Library", as object code and/or source code, so that the user can modify the Library and then relink to produce a modified executable containing the modified Library. (It is understood that the user who changes the contents of definitions files in the Library will not necessarily be able to recompile the application to use the modified definitions.) b) Use a suitable shared library mechanism for linking with the Library. A suitable mechanism is one that (1) uses at run time a copy of the library already present on the user's computer system, rather than copying library functions into the executable, and (2) will operate properly with a modified version of the library, if the user installs one, as long as the modified version is interface-compatible with the version that the work was made with. c) Accompany the work with a written offer, valid for at least three years, to give the same user the materials specified in Subsection 6a, above, for a charge no more than the cost of performing this distribution. d) If distribution of the work is made by offering access to copy from a designated place, offer equivalent access to copy the above specified materials from the same place. e) Verify that the user has already received a copy of these materials or that you have already sent this user a copy. For an executable, the required form of the "work that uses the Library" must include any data and utility programs needed for reproducing the executable from it. However, as a special exception, the materials to be distributed need not include anything that is normally distributed (in either source or binary form) with the major components (compiler, kernel, and so on) of the operating system on which the executable runs, unless that component itself accompanies the executable. It may happen that this requirement contradicts the license restrictions of other proprietary libraries that do not normally accompany the operating system. Such a contradiction means you cannot use both them and the Library together in an executable that you distribute. 7. You may place library facilities that are a work based on the Library side-by-side in a single library together with other library facilities not covered by this License, and distribute such a combined library, provided that the separate distribution of the work based on the Library and of the other library facilities is otherwise permitted, and provided that you do these two things: a) Accompany the combined library with a copy of the same work based on the Library, uncombined with any other library facilities. This must be distributed under the terms of the Sections above. b) Give prominent notice with the combined library of the fact that part of it is a work based on the Library, and explaining where to find the accompanying uncombined form of the same work.

Info

Target asset types: Software
Region / jurisdiction: Worldwide
Validity: Perpetual
Source: https://spdx.org/licenses/LGPL-2.1-only.html
Legal code: https://www.gnu.org/licenses/old-licenses/lgpl-2.1-standalone.html
This description is published under: Creative Commons Attribution 4.0 International
Publisher: Free Software Foundation
SPDX identifier: LGPL-2.1-only on the SPDX license list
DALICC identifier: LGPL-2.1-only

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/LGPL-2.1-only",
  "license-title": "GNU Lesser General Public License v2.1 only",
  "spdx-id": "LGPL-2.1-only",
  "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/LGPL-2.1-only> .

RDF, JSON-LD

{
  "@context": {
    "cc": "http://creativecommons.org/ns#"
  },
  "@id": "https://example.org/my-work",
  "cc:license": {
    "@id": "https://dalicc.net/licenselibrary/LGPL-2.1-only"
  }
}

HTML attribution

<p>This work is licensed under <a href="https://dalicc.net/licenselibrary/LGPL-2.1-only" rel="license">GNU Lesser General Public License v2.1 only</a>.</p>

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

Badge

Markdown

[![License: GNU Lesser General Public License v2.1 only](https://dalicc.net/license-library/LGPL-2.1-only/badge.svg)](https://dalicc.net/license-library/LGPL-2.1-only)

HTML

<a href="https://dalicc.net/license-library/LGPL-2.1-only"><img src="https://dalicc.net/license-library/LGPL-2.1-only/badge.svg" alt="License: GNU Lesser General Public License v2.1 only"></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: 15 recorded, 10 applied to the record, 0 proposed

The record models version 2.1 of the GNU Lesser General Public License as the -only reading. Its operative terms are those of version 2 of the Library GPL: the same numbered sections, the same whole-work reciprocity as a license-wide cc:ShareAlike duty, the same duties on distribute, modify and derive, and the same warranty and liability clauses. The one substantive difference is in the linking exception, where section 6 of version 2.1 adds the shared-library mechanism as an alternative way of meeting the condition.

15 findings

major Rubric 3 odrl:permission applied

Section 1 grants the verbatim-copy right ("You may copy and distribute verbatim copies of the Library's complete source code as you receive it, in any medium") and section 2 the right to modify and to distribute the modified work, so the record permits reproduce, distribute, modify, derive, display, present, commercial use, derivative works and modified works. Section 1 also allows a fee for the physical act of transferring a copy, so dalicc:chargeDistributionFee is permitted.
major Rubric 4 odrl:prohibition applied

Section 8 reads: "You may not copy, modify, sublicense, link with, or distribute the Library except as expressly provided under this License." dalicc:sublicense is therefore prohibited, and so is dalicc:ChangeLicense, because sections 1, 2c and 6 require the work and every work based on it to stay under this License. The sibling records GPL-2.0-only, GPL-3.0-only and LGPL-3.0-only prohibit dalicc:ChangeLicense but carry no sublicensing statement, so this record states one more prohibition than its siblings.
minor Rubric 4 odrl:prohibition applied

dalicc:promote is prohibited to stay with the four existing GNU records, which all carry it. The text of this license has no trademark or endorsement clause, so the prohibition is a library convention here and not text-supported. The review of GPL-2.0-only proposed removing it library-wide; the same question applies to this record.
major Rubric 5 odrl:duty applied

Section 2c requires that "You must cause the whole of the work to be licensed at no charge to all third parties under the terms of this License", which is whole-work reciprocity and not file-level reciprocity, so cc:ShareAlike hangs off the odrl:Set itself, exactly as on GPL-2.0-only and LGPL-3.0-only. cc:Attribution, cc:Notice and cc:SourceCode are duties on distribute, modify and derive (sections 1, 2 and 4), and dalicc:modificationNotice on modify and derive (section 2b, "cause the files modified to carry prominent notices stating that you changed the files and the date of any change").
minor Rubric 6 dalicc:WarrantyOrLiabilityAcceptance applied

Section 1 lets a redistributor sell its own warranty: "You may charge a fee for the physical act of transferring a copy, and you may at your option offer warranty protection in exchange for a fee." That is the clause dalicc:WarrantyOrLiabilityAcceptance is for. The existing GNU records leave it out although their texts carry the same sentence, so the family is not uniform on this field.
minor Rubric 6 dalicc:additionalClauses applied

Section 6 (the linking exception: a work that uses the Library may be distributed under terms of your choice if the conditions of that section are met) and section 7 (combined libraries) carry the whole difference between this license and the GPL, and no deontic term can hold them. Both are quoted verbatim in dalicc:additionalClauses, the way LGPL-3.0-only quotes the equivalent sections 4 and 5 of version 3.
info Rubric 7 cc:jurisdiction none

The text names no legal system for the grant, so cc:jurisdiction stays dalicc:worldwide and dalicc:validityType stays dalicc:perpetual. Section 12 allows the copyright holder to add a geographical distribution limitation, but that is an option the licensor may take, not a limit this license imposes.
gap Rubric 8 dalicc:additionalClauses none

Three clauses have no vocabulary term. Section 8 terminates the license automatically on breach (proposed term: dalicc:terminatesOnBreach, a property over the existing dalicc:terminationOnBreach concept). Section 11 forbids distribution where a patent claim would make royalty-free redistribution impossible (proposed term: dalicc:patentFreedomCondition). Section 10 forbids imposing further restrictions on the recipients (dalicc:addLimitation exists and could carry it, but no record uses it as a prohibition yet, so it is left open for the association's decision).
info Rubric 8 dalicc:orLaterVersionOption applied

dalicc:orLaterVersionOption false records that this is the 2.1-only reading. Section 13 gives the option of a later version only where the Library itself says "any later version", which is what the -or-later SPDX id expresses; the library models that with this flag instead of a second record.
info Rubric 9 record none

The consistency check with the axioms of dg_default returned no conflicts. Share-alike is required while dalicc:ChangeLicense is prohibited and odrl:grantUse is not permitted, so the share-alike rule of the checker is not triggered.
info Rubric 2 odrl:target applied

One odrl:AssetCollection of dct:type dcmitype:Software, following GPL-2.0-only and LGPL-3.0-only. The license speaks of a software library throughout.
info Rubric 10 record none

The record follows GPL-2.0-only statement for statement, plus the linking exception in dalicc:additionalClauses that LGPL-3.0-only carries for version 3. The two differences from the siblings are deliberate and are described in the rubric 4 and rubric 6 findings.
info Rubric 10 dalicc:additionalClauses none

Against LGPL-2.0-only the operative difference is section 6, which in version 2.1 offers five ways of meeting the condition instead of four: option b, "Use a suitable shared library mechanism for linking with the Library", is new, and the later options are renumbered. The preamble was rewritten and the license renamed from Library to Lesser, which changes no obligation. Both differences are inside the quoted clause, so the deontic models of the two records are identical.
minor Rubric 4 odrl:prohibition applied

dalicc:promote was prohibited and no sentence of this text supports it. The statement was the library's reading of a legal default, that a copyright licence which says nothing about endorsement grants no right to it, and it sat in 519 of 581 records as a house convention. That reading is now an adopted dalicc:DefaultRule of the core dependency graph, which supplies it to every licence that is silent about the action, so a compatibility check reaches the same answer and the record states only what the text states. Removed on 2026-09-23; see section 13 of docs/LICENSE_REVIEW.md.
major Rubric 10 dalicc:compatibleWith applied

Section 3 reads: "You may opt to apply the terms of the ordinary GNU General Public License instead of this License to a given copy of the Library." and adds "(If a newer version than version 2 of the ordinary GNU General Public License has appeared, then you can specify that version instead if you wish.)" dalicc:compatibleWith names GPL-2.0-only, GPL-2.0-or-later, GPL-3.0-only, GPL-3.0-or-later.

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.

Version 2 current2026-09-24 Giray Havur

The changes since version 1 left endorsement to the default rule of the core dependency graph, recorded which sentence of the text each statement rests on, named the license the record itself is published under and recorded the licenses a work under it may be released under.

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10 changes
- removed prohibition dalicc:promote
  
  Manual edit The endorsement prohibition rested on no sentence of the text; the default rule for endorsement now supplies it.
- changed duty cc:ShareAlike
  
  was duty cc:ShareAlike
  
  Manual edit The statement now quotes the sentence of the licence text it rests on: "You must cause the whole of the work to be licensed at no charge to all third parties under the terms of this License."
- changed permission odrl:derive with duties [cc:Attribution, cc:Notice, cc:SourceCode, dalicc:modificationNotice]
  
  was permission odrl:derive with duties [cc:Attribution, cc:Notice, cc:SourceCode, dalicc:modificationNotice]
  
  Manual edit Its duty dalicc:modificationNotice quotes "You must cause the files modified to carry prominent notices stating that you changed the files and the date of any change."
- changed permission odrl:modify with duties [cc:Attribution, cc:Notice, cc:SourceCode, dalicc:modificationNotice]
  
  was permission odrl:modify with duties [cc:Attribution, cc:Notice, cc:SourceCode, dalicc:modificationNotice]
  
  Manual edit Its duty dalicc:modificationNotice quotes "You must cause the files modified to carry prominent notices stating that you changed the files and the date of any change."
- changed prohibition dalicc:sublicense
  
  was prohibition dalicc:sublicense
  
  Manual edit The statement now quotes the sentence of the licence text it rests on: "You may not copy, modify, sublicense, link with, or distribute the Library except as expressly provided under this License."
- 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.
- added dalicc:compatibleWith dalicclib:GPL-2.0-only
  
  Manual edit Section 3 reads: "You may opt to apply the terms of the ordinary GNU General Public License instead of this License to a given copy of the Library." and adds "(If a newer version than version 2 of the ordinary GNU General Public License has appeared, then you can specify that version instead if you wish.)"
- added dalicc:compatibleWith dalicclib:GPL-2.0-or-later
  
  Manual edit Section 3 reads: "You may opt to apply the terms of the ordinary GNU General Public License instead of this License to a given copy of the Library." and adds "(If a newer version than version 2 of the ordinary GNU General Public License has appeared, then you can specify that version instead if you wish.)"
- added dalicc:compatibleWith dalicclib:GPL-3.0-only
  
  Manual edit Section 3 reads: "You may opt to apply the terms of the ordinary GNU General Public License instead of this License to a given copy of the Library." and adds "(If a newer version than version 2 of the ordinary GNU General Public License has appeared, then you can specify that version instead if you wish.)"
- added dalicc:compatibleWith dalicclib:GPL-3.0-or-later
  
  Manual edit Section 3 reads: "You may opt to apply the terms of the ordinary GNU General Public License instead of this License to a given copy of the Library." and adds "(If a newer version than version 2 of the ordinary GNU General Public License has appeared, then you can specify that version instead if you wish.)"
Version 1

Created from the license text on 2026-09-15 (GNU family).

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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.

Variants

2 records in the library model this same legal text with one thing changed: the option of a later version, an exception that lifts one condition, or a rider that adds one. Each of them is a license of its own and is listed like any other. See variant in the glossary.

GNU Lesser General Public License v2.1 or later Or-later form
GNU Lesser General Public License v2.1 only with Qt LGPL exception 1.1 With an exception

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.