Open source licensing notices in Web applications 81 Open source licensing notices in Web applications Arnoud Engelfriet a (a) Associate, ICTRecht Legal Services. DOI: !".5033/ifosslr.v3i1.&' Abstract More and more applications are moving to the Web. Often, such applications present a combination of client- and server-side code. Almost all FOSS licenses re uire an e!plicit notice in the code regarding the license applicability and sometimes even the entire license te!t. #o$ever, for Web applications this approach can add significant performance penalties. In this article I discuss the theory and practice of various approaches to$ards this issue. Keywords &a$' information technolog"' Free and Open Source Soft$are' Web applications Linking to open source licenses Open source soft$are is freel" available for an"one, including source code. (he license grants ever"one permission to adapt or improve the source code, for e!ample to fi! errors, to ma)e a more efficient implementation or to add completel" ne$ functionalit". (he soft$are ma" also be copied and distributed freel", even in modified form. #o$ever, open source soft$are is not public domain. (he soft$are is protected b" cop"right and one must accept the license terms before the soft$are may be modified and distributed. With open source licenses it is not re uired to e!plicitl" sign an agreement $ith the author. ("picall" the author merel" adds a license statement in the source code to put recipients on notice. %ncluding complete license te!ts in source code is of course sufficient, but for *avascript applications often impractical. For intentional source code distributions, e.g. a do$nloadable +ipfile $ith the full code and documentation it ma" be acceptable to add a license te!t, but if the *avascript code is do$nloaded as part of a Web page, the overhead may be significant. (he uestion then arises, is it sufficient to merel" refer to a license that is published else$here, e.g. b" linking to the license te!t on opensource.org? International Free and Open Source Soft$are Law -evie$ .ol. 3, %ssue 1 82 Open source licensing notices in Web applications Consequences of insufficient license notice When considering if a license notice is sufficient, one must also consider the conse uences of an insufficient notice. (he onl" conse uence % can think of is that the recipient of the file cannot claim an" usage right under the license in uestion. As a result, that recipient cannot use or distri(ute the file. Without a license, basic cop"right applies and cop"right forbids the reuse or redistribution of soft$are without ade uate permission. A difficult situation ma" arise if the license notice is accompanied b" a te!t such as 1(his program is free soft$are' you can redistribute it and/or modify it under the terms of the G4&5. Such a te!t is b" itself a permission 6a mini-license7 to freel" redistribute and/or modif" the code. (he terms of the 34& could be declared inapplicable if the reference is insufficient. As a result, a recipient $ould have unlimited permission to redistribute or modif", $ithout an" obligation under the 34&. Literature review (he legal literature is surprisingl" silent on this issue. .an &indberg, Intellectual )ro)ert* and o)en source, O8-eill" 2008 6p. 150) recommends to simpl" use a reference and store the license te!t itself some$here in the source distribution. Other standard $or)s, such as -osen, O)en source licensing, 4rentice #all 099; and St. &aurent, +nderstanding O)en Source and ,ree Soft-are Licensing, O8-eill" 099; do not discuss $hether one can merel" refer to a license te!t outside the files one distributes. One relevant article is -ichard M. Stallman, <(he *avaScript (rap’, ./+.org *ul" 31, 2010 http:22$$$.gnu.org/philosoph"2>avascript-trap.html. (his article ackno$ledges that 1the G?@ G4& is long enough that including it in a page $ith a *avaScript program can be inconvenient5 and proposes a convention that uses the mar)ers @licstart and @licend to mar) the beginning and end of license references. (he convention suggests to use a te!t li)e this: The 0avaScript code in this )age is free soft-are: *ou can redistri(ute it and/or 1odify it under the terms of the ./+ .eneral 2u(lic License (G/+ .2L) as )u(lished (y the ,ree Soft-are ,oundation, either version 3 of the License, or (at *our o)tion) any later version. The code is distributed 3IT4O+T A/5 3ARRA/TY; -ithout even the im)lied -arranty of 7ERC4A/TA8ILITY or ,IT/ESS ,OR A 2ARTIC+LAR 2+R2OSE. See the ./+ .2L for 1ore details. (his convention appears to be used in some larger Javascript-based pro>ects 6such as Plone7 but is not universally adopted. International Free and Open Source Soft$are Law -evie$ .ol. 3, %ssue 1 Open source licensing notices in Web applications 83 Applicability as stated in open source license Open source licenses themselves often contain statements about ho$ the" can be declared applicable to certain soft$are. These statements may allo$ or instead bloc) the use of e!ternal references. The GNU General Public License (he most popular open source license is the 3?@ 3eneral 4ublic &icense or 34&. .ersion 0 of this license states: This License ap)lies to an* )rogram or other -or9 -hich contains a notice )laced (* the co)*right holder sa*ing it 1a* (e distri(uted under the terms of this .eneral 2u(lic License. (he recommended format for this notice 6as given belo$ the official te!t on [email protected]) contains the line This )rogram is free soft-are; *ou can redistri(ute it and/or 1odify it under the terms of the ./+ .eneral 2u(lic License as )u(lished (* the ,ree Software ,oundation; either version : of the License, or (at *our o)tion) an* later version. ... 5ou should have received a co)* of the ./+ .eneral 2u(lic License along -ith this )rogram; if not, -rite to the ,ree Software ,oundation, Inc., #; Te1)le 2lace, Suite 330, 8oston, 7A ":!!!< 1307 +SA. .ersion of the 34& has no e!plicit statement about ho$ to recogni+e $hether a $or) is licensed under G4&v3. There is only this sentence= “The 2rogram” refers to any co)*righta(le -ork licensed under this License. At the bottom an e!ample is given, $hich has the same te!t as for 34&v2. We ma" thus assume that the intent is the same for 34&v2 and v3. (he 34& in other $ords does not provide an" obstacles against merely referring to the G4& te!t at an e!ternal location. GNU Lesser General Public License (he G?@ Lesser General Public License has a very similar clause in version 2.1= This License Agree1ent ap)lies to an* soft-are li(rary or other )rogram -hich contains a notice )laced (* the co)*right holder or other authori?ed )arty sa*ing it 1a* (e distri(uted under the terms of this Lesser .eneral 2u(lic License (also called @this License") (herefore the &34&, li)e the 34&, does not provide an" obstacles against merel" referring to the 34& te!t at an e!ternal location. The Mo"illa Public License 1.1 International Free and Open Source Soft$are Law -evie$ .ol. 3, %ssue 1 84 Open source licensing notices in Web applications (he MP& uses an e!plicit source code notice in an Axhibit to the license te!t. (his notice contains the follo$ing te!t= The contents of this file are su(Aect to the 7o?illa 2u(lic License Bersion 1.! (the @License"); *ou 1a* not use this file eCce)t in co1)liance -ith the License. 5ou 1a* o(tain a co)y of the License at htt) %%---.1o?illa.org/M2L/ With this te!t it is clear that a mere reference to the license te!t can suffice. The B&' license (he BSC license is a bit more problematic. (he license does not define $hich soft$are is covered b" it. The only reference is article 1 of the license= Redistri(utions of source code 1ust retain the a(ove co)*right notice, this list of conditions and the follo-ing disclaimer. (his ma)es it clear that the license te!t must be in the file to $hich the license applies. Furthermore, the BSC license is t"picall" offered as a template so that linking to that te!t results in an incomplete license. (his reinforces the interpretation that one must cop" the license te!t 6and substitute one8s details as cop"right holder7 before the BSC license can appl". Arguabl" one can interpret the $ord 1retain5 as 1do not remove5 $ithout an obligation to actuall" include the notice and the conditions in an" source file. Under this interpretation it could be sufficient to refer to the BSC license else$here on the World-Wide Web. One $ould still need to ma)e a cop" of the BSC license template and substitute one8s details. The M(T license (he MI( license is a very brief and liberal open source license. The license te!t states that the license applies to an* )erson o(taining a co)y of this soft-are and associated docu1entation files but also re uires that The a(ove co)*right notice and this )ermission notice shall (e included in all co)ies or su(stantial )ortions of the Software. (his re uirement ma)es it hard to compl" $ithout actuall" including the verbatim te!t of the license in the Javascript file.