GPL — legal particularities

Soft­ware with open source code can be reused as OER. There are spe­cial licenses for the licens­ing of soft­ware. Open in the sense of OER are the licenses of the Open Source Ini­tia­tive (OSI). In this blog post, we present one of the OS licenses: the Gen­eral Pub­lic License (GPL).

GPL — legal particularities

As part of the twillo project, con­sid­er­a­tion was given to using the text edit­ing pro­gram CKEd­i­tor. This is licensed under the GNU Gen­eral Pub­lic License (GPL) ver­sion 2 or later(https://github.com/ckeditor/ckeditor4/blob/master/LICENSE.md; https://www.gnu.org/licenses/gpl.html ). Twillo is an open project. We strive to use open source soft­ware with few restric­tions. The fol­low­ing three ques­tions there­fore arose dur­ing the intro­duc­tion of the pro­gram:

1. Is the GPL license com­pat­i­ble with the open­ness of the project?
2. Isn’t the license notice: “GPLv2 or later” ambigu­ous?
3. What spe­cial fea­tures (pit­falls) does the GPL have from a legal point of view?
   

1. is the GPL license compatible with the openness of the project?

GNU Gen­eral Pub­lic License (GPL) is an open license in the sense of an open source ini­tia­tive despite a strict “copy­left”.

Open source licenses are divided into three dif­fer­ent lev­els when imple­ment­ing the “copy­left” prin­ci­ple:

• • with strict “Copy­left” (GPL),
  • with lim­ited “Copy­left” (LGPL) and
  • with­out “Copy­left” (BSD)
    

Strict “copy­left” means: If soft­ware under a strict “copy­left” license is com­bined with your own soft­ware and dis­trib­uted, the over­all result must be passed on under the strict license, the so-called viral effect. This oblig­a­tion applies even if only a small part of soft­ware with a strict “copy­left” is used to pro­duce your own soft­ware. As long as the CKEd­i­tor is only used as part of the project and not fur­ther devel­oped, the strict “copy­left” is irrel­e­vant.

2. is the license notice: “GPLv2 or later” not ambiguous?

The ver­sion note “GPL v.2 or later” is not ambigu­ous, but is com­mon for the licens­ing of soft­ware.

Accord­ing to sec­tion 9 GPL v2 and sec­tion 14 para. 2 GPL v3, the devel­op­ers of the orig­i­nal pro­gram have two options to spec­ify under which license version(s) of the GPL the code may be used:

• “any later” ver­sion note: use under the spec­i­fied ver­sion or any later ver­sion is per­mit­ted
• open ver­sion note: use is per­mit­ted under any ver­sion (includ­ing older ver­sions)
  

Not con­trac­tu­ally stip­u­lated, but also rec­og­nized: Deci­sion for a spe­cific license ver­sion (e.g. Linux-Ken­nel: GPLv2). How­ever, such a deci­sion does not nor­mally appear to make sense, as this does not guar­an­tee that the license terms can be adapted to chang­ing cir­cum­stances.

Special features of the “any later” version note

If the GPL soft­ware is edited, the edi­tors are ini­tially bound by the ver­sion notice of the orig­i­nal soft­ware. They can­not change this if the orig­i­nal code is affected. How­ever, if inde­pen­dent code is devel­oped that is not mixed with the orig­i­nal code (e.g. saved in a sep­a­rate file), it is pos­si­ble to assign a sep­a­rate pro­gram part to a sep­a­rate release note. In this case, the sep­a­rate release note may dif­fer from the release note of the orig­i­nal author.

Regard­less of the ver­sion notice, licensees must com­mit to a spe­cific license ver­sion. If they wish to switch to a new license ver­sion when it is pub­lished, this can have both pos­i­tive and neg­a­tive con­se­quences for them (e.g. the new ver­sion grants more rights than the pre­vi­ous ver­sion or restricts old rights and pro­vides for new oblig­a­tions in return).

If the licensees decide to com­ply with the new license ver­sion from now on, the new terms of use shall apply. They hereby declare their accep­tance of a new license agree­ment under the amended con­di­tions. This deci­sion does not nec­es­sar­ily have to be doc­u­mented exter­nally. This means that it will usu­ally be dif­fi­cult for out­siders to assess which license ver­sion applies to the respec­tive users. How­ever, this knowl­edge can be par­tic­u­larly impor­tant for licen­sors if they want to take action against a user for vio­lat­ing the GPL and the poten­tial vio­la­tion lies in an action that would be per­mit­ted under one license ver­sion but not under another. The fol­low­ing applies here: If the licensees take actions that are only per­mit­ted under a new license ver­sion (i.e. if it con­tains more exten­sive pow­ers), they hereby tac­itly declare that they wish to switch to the new license ver­sion. This results in the con­clu­sion of a license agree­ment under the amended con­di­tions. If you do not com­ply with any fur­ther legal oblig­a­tions, this will result in a breach of the GPL and the rights under the license will expire.

Recommendation: License version 3

We rec­om­mend using the cur­rent ver­sion 3, which was intro­duced in 2007 and has sev­eral advan­tages over ver­sion 2 from 1991, in par­tic­u­lar its improved com­pat­i­bil­ity with other licenses. The cur­rent ver­sion 3 has been adapted to new legal require­ments and has filled the gaps in the old ver­sion (patent com­pen­sa­tion, inter­na­tion­al­iza­tion and reme­dies for license infringe­ments).

What’s new in the current version?

The GPLv3 of June 29, 2007 con­tains the basic inten­tion of the GPLv2, but the lan­guage of the license text has been changed con­sid­er­ably and is much more exten­sive due to tech­ni­cal and legal changes and the inter­na­tional exchange of licenses.

The new license ver­sion con­tains a num­ber of new clauses. These address issues that were not or only insuf­fi­ciently reg­u­lated in ver­sion 2 of the GPL. The fol­low­ing overview presents the most impor­tant new reg­u­la­tions:

a) GPLv3 con­tains com­pat­i­bil­ity rules that make it eas­ier than before to com­bine GPL code with code pub­lished under other licenses (relax­ation of the strict “copy­left” effect). This applies in par­tic­u­lar to code under the Apache license v. 2.0. GPLv3 is com­pat­i­ble with the fol­low­ing licenses, among oth­ers:

Apache License, Ver­sion 2

Affero Gen­eral Pub­lic License, Ver­sion 3 (see sec­tion 13 of the GPLv3)

Lesser Gen­eral Pub­lic License, Ver­sions 2, 2.1 and 3 (LGPL)

BSD license with­out adver­tis­ing clause

CeCILL (CONTRAT DE LICENCE DE LOGICIEL LIBRE CeCILL)

Artis­tic License 2.0

Zope Pub­lic License, Ver­sion 2.0 and 2.1

b) Reg­u­la­tions on dig­i­tal rights man­age­ment have been added. This is intended to pre­vent GPL soft­ware from being mod­i­fied at will because users invoke the legal reg­u­la­tions in order to be pro­tected by tech­ni­cal pro­tec­tion mea­sures (such as DMCA or Copy­right Direc­tive).

c) In con­trast to v2, the cur­rent ver­sion includes a cure clause . Accord­ing to this, a breach of the license can be cured — the licensees retain their rights — if they act in accor­dance with the law.

d) GPLv3 con­tains an explicit patent license. When licens­ing a pro­gram with GPL, both copy­rights and patents can now be licensed, inso­far as this is nec­es­sary for the use of the licensed code. This does not grant a com­pre­hen­sive patent license. Fur­ther­more, the new patent clause aims to pro­tect users from the con­se­quences of agree­ments between patent hold­ers and GPL licensees that only ben­e­fit some of the licensees. Accord­ing to the patent clause, licensees are obliged to ensure that either every user can enjoy the ben­e­fits (patent license or exemp­tion from claims) or that no one can ben­e­fit from them

e) In con­trast to GPLv2, GPLv3 makes it clear that there is no oblig­a­tion to dis­close the source code for ASP use of GPL pro­grams as long as no copy of the soft­ware is sent to the client. If the copy­left effect is to be extended to ASP use, the Affero Gen­eral Pub­lic License, Ver­sion 3 (AGPL) must be applied, which dif­fers from the GPLv3 only in this respect.

3. what are the special legal features and pitfalls of the GPL?

Applic­a­ble law:

Accord­ing to inter­na­tional copy­right law, the so-called coun­try of pro­tec­tion prin­ci­ple applies to infringe­ments with a for­eign con­nec­tion. Accord­ingly, the copy­right law of the coun­try for whose ter­ri­tory copy­right pro­tec­tion is claimed applies. If copy­right pro­tec­tion is sought for Ger­man ter­ri­tory, Ger­man copy­right law applies.

Exam­ple: If a for­eign author seeks injunc­tive relief under copy­right law due to an infringe­ment of rights in Ger­many, Ger­many is the coun­try of pro­tec­tion. The injunc­tive relief is based on Sec­tion 97 (1) UrhG.

Con­clu­sion of con­tract:

The exact point in time at which the con­tract is con­cluded is impor­tant, as the pro­vi­sions of the GPL with its rights and oblig­a­tions come into effect from this point in time. If the user receives the soft­ware includ­ing the license file, this does not yet con­sti­tute a license agree­ment. Accord­ing to Ger­man con­tract law, this requires two con­cur­ring dec­la­ra­tions of intent, offer and accep­tance. In addi­tion, the con­tent of the con­tract must be clearly defin­able. The con­trac­tual offer lies in the attached license agree­ment and is there­fore eas­ily deter­minable. This is an offer to any­one. The offer is only accepted when the user can rea­son­ably read the text of the con­tract and vis­i­bly man­i­fests accep­tance of the offer to the out­side world. The license agree­ment is there­fore only con­cluded when the user mod­i­fies or passes on the pro­gram (i.e. makes use of the rights of use from the license). Pass­ing on means, for exam­ple, that the soft­ware is offered to third par­ties for down­load or CD-ROMs with the pro­gram are pro­duced.

Rights of use:

If the license terms are not observed by the user, this can lead to the expiry of the right to use and dis­trib­ute the soft­ware, Sec­tion 158 (1) BGB. In this case, the licen­sor has a claim for injunc­tive relief against the user under Sec­tion 97 (1) sen­tence 1 UrhG. In addi­tion to civil law claims, a vio­la­tion of license terms in the event of dis­tri­b­u­tion of the soft­ware may have crim­i­nal law con­se­quences for the user pur­suant to Sec­tions 106, 108 UrhG.

Under Ger­man licens­ing law, the expi­ra­tion of the license results not only in the expi­ra­tion of the license vis-à-vis the soft­ware man­u­fac­turer, but also vis-à-vis its customers/users. In con­trast to the dis­tri­b­u­tion of tan­gi­ble prop­erty, there is no “acqui­si­tion of rights in good faith” for intel­lec­tual prop­erty. This means that the end user does not acquire any rights to the soft­ware in good faith if he/she did not know or should not have known of the license infringe­ment.

Rights and oblig­a­tions:

Impor­tant: The fol­low­ing overview is for guid­ance only and rep­re­sents the most impor­tant rights and oblig­a­tions under GPLv2 and v3. For all rights and oblig­a­tions, please refer to the offi­cial text of the license in Eng­lish:

for GPL v2: https://www.gnu.org/licenses/old-licenses/gpl‑2.0

for GPL v3: https://www.gnu.org/licenses/gpl‑3.0.en.html

Rights:

The GPL grants the right to repro­duce, edit and dis­trib­ute the pro­gram in an unchanged or mod­i­fied ver­sion. Under copy­right law, this con­sti­tutes the grant­ing of sim­ple (“non-exclu­sive”) rights of use.

Duties:

1. Deliv­ery of the license text

Accord­ing to sec­tion 1 GPLv2 and sec­tion 4 GPLv3, a copy of the license text must be sup­plied with each copy of the pro­gram. This can be done in phys­i­cal form as a paper print­out or non-phys­i­cally by attach­ing a cor­re­spond­ing text file. This oblig­a­tion ensures that every pur­chaser is aware of the pos­si­bil­ity of acquir­ing rights under the GPL and receives the offer to con­clude a license agree­ment.

2. Copy­right notice

Clause 1 GPLv2 and clauses 4, 5b GPLv3 stip­u­late that a copy­right notice/license notice must be attached to each copy in a clearly vis­i­ble man­ner. In addi­tion, exist­ing copy­right notices/license notices may not be removed. This is intended to make it clear who owns the rights to the soft­ware.

3. Exclu­sion of lia­bil­ity and war­ranty

Sec­tion 1 GPLv2 stip­u­lates the oblig­a­tion to include a ref­er­ence to the exclu­sion of lia­bil­ity on each copy and to adopt exist­ing ref­er­ences to it unchanged. Sec­tion 15 of GPLv3 pro­vides for a com­pre­hen­sive exclu­sion of lia­bil­ity. Such an exclu­sion of lia­bil­ity in pre-for­mu­lated con­tracts (license agree­ment as gen­eral terms and con­di­tions, Sec­tion 305 et seq. of the Ger­man Civil Code) is not com­pat­i­ble with Ger­man law on gen­eral terms and con­di­tions. Accord­ing to § 309 ff. BGB, lia­bil­ity for intent and gross neg­li­gence may not be excluded in gen­eral terms and con­di­tions. A com­plete exclu­sion of war­ranty in accor­dance with sec­tion 14 of GPLv3 is also not per­mit­ted, as the soft­ware is equiv­a­lent to a newly man­u­fac­tured item. As the clauses are inef­fec­tive under Ger­man law, the statu­tory pro­vi­sions take their place:

Due to the gra­tu­itous nature of the soft­ware trans­fer, the con­tract is to be clas­si­fied as a mixed gift con­tract. The devel­op­ers are only liable for intent and gross neg­li­gence. They only have war­ranty oblig­a­tions if they have fraud­u­lently con­cealed the defect in the soft­ware. Since fraud­u­lent con­ceal­ment is usu­ally dif­fi­cult to prove in prac­tice, war­ranty claims against the devel­op­ers are hardly enforce­able.

4. Pass­ing on the source code

Pass­ing on the object code obliges you to pass on the source code, sec­tion 3 of the GPLv2 or sec­tion 6 GPLv3.

Pos­si­bil­i­ties for pass­ing on the source code:

• • Deliv­ery on a stan­dard data car­rier, together with the object code,
  • Deliv­ery of only the object code with a writ­ten promise to deliver the source code on the same data car­rier on which the object code was deliv­ered at cost price upon request,
  • Any­one who does not pass on the object code com­mer­cially and has received it within the frame­work of an agree­ment men­tioned above can refer to the orig­i­nal agree­ment with regard to the source code.
  • through online access: If you offer an object code under a net­work address, you can also offer the source code under the same address.

These options are exhaus­tive and can­not be com­bined with each other (e.g. deliv­ery of the object code on a data car­rier (as under a.) and pub­li­ca­tion of the source code online (as under d.) is not pos­si­ble).

5. Pro­hi­bi­tion of license fees

No license fee may be charged for the repro­duc­tion and dis­tri­b­u­tion of the GPL soft­ware. Excluded from this is the fee for copy­ing costs, the costs for the cre­ation of a man­ual and for ser­vices asso­ci­ated with the pur­chase of the soft­ware.

6. Oblig­a­tions for pro­cess­ing

Edits must be clearly marked as such. The note must include what was edited and when.

7. Notes on third-party license con­di­tions

The man­u­fac­tur­er’s license agree­ment should typ­i­cally refer to the license con­di­tions of the free soft­ware com­po­nents and/or pass on cor­re­spond­ing third-party license con­di­tions. This can only be dis­pens­able if it is cer­tain that no such soft­ware com­po­nents have been imple­mented (which would be atyp­i­cal in prac­tice, how­ever).

8. Right to pro­vide fur­ther infor­ma­tion (ver­sion 3)

In accor­dance with GPLv3 clause 7, the fol­low­ing spe­cial notices may also be attached:

• • an exclu­sion of war­ranty or lim­i­ta­tion of lia­bil­ity devi­at­ing from sec­tions 15, 16 GPLv3 or
  • the require­ment to include spec­i­fied mean­ing­ful legal or author­ship notices in that mate­r­ial or in the appro­pri­ate legal notices dis­played by the works it con­tains, or
  • the pro­hi­bi­tion on mis­rep­re­sent­ing the ori­gin of the mate­r­ial or the require­ment to appro­pri­ately mark mod­i­fied ver­sions of the mate­r­ial as dif­fer­ent from the orig­i­nal, or
  • Limit the use of the names of licen­sors or authors of the mate­r­ial for pro­mo­tional pur­poses, or
  • reject­ing the grant­ing of rights under trade­mark law to use cer­tain prod­uct names, prod­uct or ser­vice marks or
  • the indem­ni­fi­ca­tion of the licensee and the authors of the mate­r­ial from claims of third par­ties by any­one who trans­fers the soft­ware (or mod­i­fied ver­sions thereof).