04 Licences

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Free Software LicensesPractical Issues about free licenses. Case studies

Legal AspectsMaster on Libre Software (URJC)http://master.libresoft.es

Miguel Vidal, Gregorio Robles, Jesus M. Gonzalez Barahona

{mvidal,grex,jgb}@gsyc.esGSyC/LibreSoft, Universidad Rey Juan Carlos

March 2011

Miguel Vidal, Gregorio Robles, Jesus M. Gonzalez Barahona Legal Aspects
http://master.libresoft.es/http://master.libresoft.es/http://find/


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c 2008-2011 Miguel Vidal, Gregorio Robles, Jesus M. Gonzalez-Barahona.

Some rights reserved.

This document is distributed under the Creative Commons

Attribution-ShareAlike 3.0 license, available in

http://creativecommons.org/licenses/by-sa/3.0

The original version of this document is available at

http://master.libresoft.es

http://creativecommons.org/licenses/by-sa/3.0http://master.libresoft.es/http://master.libresoft.es/http://creativecommons.org/licenses/by-sa/3.0http://find/http://goback/


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Free Software Licenses

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Why Do I Need a License?


F S f Li
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Why Do I Need a License?

If you dont license your code,it cant be used (legally) by other people.


F S ft Li
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Licenses: Concepts

An unilateral contract between the author and the user.

Grants some rights to the users of copyrighted work.You dont need to sign the contract, but in that case, youdont have any rights over the copyrighted work.

EULA is not necessary.

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FLOSS Licensing

From least to greatest complexity (and strict):

Academic Licenses

Permissive Licenses

Partially Closable Licenses (weak copyleft)

Reciprocal Licenses (strong copyleft)


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BSD Licenses

Origins:

BSD (Berkeley Software Distribution) is a Unix flavor

developed by University of Berkeley (CA).BSD Unix was licensed under a minimalistic license whichpermits both source or binary redistribution; alsomodifications, but without any other restriction.

Several revisions (its a template)


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BSD License

Based in original BSD license.

Very popular (BSD userland, PF, TCP/IP, OpenSSH,TCL/Tk...).

You may redistribute the work, in any form (source or binary)but with all remaining copyright notes (authorshipattribution).

There is a no warranty clause. Very criticized, this clause is

for avoiding legal problems with the use of software and isalso very usual in proprietary software.




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Practical Issues about free licenses. Case studies

The 2-clause BSD License

Copyright (C) (owner). All rights reserved.Redistribution and use in source and binary forms, with or withoutmodification, are permitted provided that the following conditionsare met:

1 Redistributions of source code must retain the above copyrightnotice, this list of conditions and the following disclaimer.

2 Redistributions in binary form must reproduce the abovecopyright notice, this list of conditions and the following

disclaimer in the documentation and/or other materialsprovided with the distribution.




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The BSD License: No Warranty

THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND

CONTRIBUTORS AS IS AND ANY EXPRESS OR IMPLIED

WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A

PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL

THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

POSSIBILITY OF SUCH DAMAGE.




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Other permissive licenses

X-Window R11 License (X11). This license applies to the mostused graphical subsystem in Unix systems. The license is very similarto BSD and is also known as MIT license. Some other derivativeworks are licensed under X11 License, such as XFree86.

Zope Public License 2.0. This license is used by the Zopedistribution (an application server) and some related products. NearBSD license, also prohibits the use of Zope Corporation trademarks.

Public domain. An intellectual work in the public domain is neither

under any IP law nor a license. Most public domain works retains,however, the authorship. For this reason, it is very similar to havethe program under PD or under a BSD license.


Free Software Licensesf C


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The Apache License v2

Old versions: 1.0 (original) and 1.1 (ASF, 2000).

Apache License 2.0 (January 2004): permissive license.

Make the license easier for non-ASF projects to use

Allow the license to be included by reference instead of listed

in every file

Require a patent license from a contributors own patents.

Over 5000 non-ASF projects located at SourceForge areavailable under Apache License (2009).

25 % from Google Code (including Android)

Compatibility with GPLv3 (only one-way). (But incompatiblewith GPLv2)


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The Mozilla Public License

Weak copyleft: the code under the MPL may be combinedwith proprietary files in one program (Larger Work)

Source code copied or changed under the MPL must stay

under the MPL.Some complex restrictions make it incompatible with the GPL.

A module covered by the GPL and a module covered by theMPL cannot legally be linked together.

For this reason, Firefox have been relicensed under multiplelicenses (MPL, GPL, LGPL).


Free Software LicensesP ti l Iss s b t f li s s C s st di s


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The GNU LGPL

LGPL = Lesser GPL

LGPL started as Library GPL. Later renamed to LesserGPL.

LGPL maintain all freedoms and restrictions to the licensed

software, but with one exception:LGPL Software can be integrated/linked with any othersoftware, without limitations (including proprietary software).

Why LGPL?

Created for promoting the use of GPL libraries in any othersoftware (ex: GNU libc).

Later, FSF checked that LGPL did not helped to the creationof new Free software, so they decided to rename it to lesserand discourage its use.


Free Software LicensesPractical Issues about free licenses Case studies


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GNU GPL License

GPL = GNU General Public License.

GPL Concepts:Created by FSF for the GNU Project.

However, very often used in non-GNU free software.

Probably, the most popular Free Software license: around

70 % Freshmeat projects licensed under GPL.Some popular software licensed under GPL: Linux, GNOME,Emacs, GCC. . .




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The GNU GPL

What makes the GPL so special?




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The GNU GPL


It was the first license to outline the copyleft principle.

All non-restrictive licenses have been based on the GPL,including Creative Commons and the Wikipedia license.

Without the GPL, copyleft would be just an idea, and FreeCulture would have not existed (as least as we know it).




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The GNU GPL


It was the first license to outline the copyleft principle.

All non-restrictive licenses have been based on the GPL,including Creative Commons and the Wikipedia license.

Without the GPL, copyleft would be just an idea, and FreeCulture would have not existed (as least as we know it).

Free licenses are the juridical-philosophical foundation of libre

software




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GNU GPL License (II)

GPL Characteristics:This license guarantees the four FLOSS freedoms.

It is though to always guarantee code freedom. This is themeaning of the copyleft clause: all derivative works should

be licensed also under the same license.Since in USA software patents are admissible, GPL includes aclause for avoiding GPL licensing of patented software oralgorithms.

GPL has three versions. The most known is GPL Version 2

because has been on the market for more than 10 years.

GPL code can not be mixed with other code underGPL-incompatible license.



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Changes in GPLv3

The newest GPL version does not invalidate previous versions orrequires software to be licensed under the new version.

Major changes

It DOES NOT prevent DRM implementations with GPLsoftware, but it DOES allow interoperable software to bewritten with it.More protection related to software patentsIt neutralizes WIPO (anti-circumvention) laws which ban libresoftware (DMCA and EUCD).It clarifies license compatibility (additional permissions)

Minor changes

Adaptation to technological innovations.Clarifications to make it easier to use and understand.Better internationalization (convey/distribution)

Many changes, but fundamental principles remain.




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Other reciprocal licenses: Affero GPL

Affero GPL (AGPL) is a free software license, copyleft-like,published by the Free Software Foundation (version 3: 2007).

It is a derived license from GPL.

It contains a clause requiring distribution of any modifiedsource code of applications running in a computer network(SaaS).

It aims to cover the case of modified GPL software which isnot distributed because the GPL license does not require todo so (web services or online applications).




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Recommended licenses

The 2-clause BSD License (academic/permissive)

The Apache License version 2.0 (permissive)

The Mozilla Public License (weak copyleft)The Lesser/Library GPL, version 2 or 3 (weak copyleft)

The GNU GPL, version 2 or 3 (strong copyleft)

The Affero GPL, version 3 (strong copyleft)




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Compatibility

Compatibility == merge source code from different libre softwarelicenses.

GPLv3 increases compatibility with several free licenses

(Apache, Affero).Allow additional requirements:

Responsibility: Allows add disclaimers or warranty notes.Allows add restrictions about trademarks.

GPLv3 is more modular, more compatible, and will be compatiblewith different copyleft licenses.




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Practical Issues about free

licenses. Case studies




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Choosing a free license: previous criteria

Each project has its own goals and criteria related to licensingissues.

The main criteria of differentiation is existence (or not) ofreciprocity pacts.

Other copyleft licenses have a limited effect, which appliesonly to the work (or component) original (weak copyleft).

Dual licensing policies.


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Choosing a free license: When?

When we want to guarantee some basic freedoms, common toall free software.

When we want a work achieves the highest use and

dissemination.When we impose certain conditions or restrictions (therecognition of authorship, lack of liability, extra warranties,trademarks, etc.)

When we want to maintain control over the evolution of theprogram (copyleft).




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Choosing a free license: Cases

Do I want to allow privatization of derivative works?

Do I want developers return their modifications to thecommunity, or me as original author, in particular?

Do I want to allow licensees to merge or link their program

with mine?Do I want widespread coverage and/or try to establish astandard?

Should my program run with one in particular? Have it any

restrictions?Is there risk that someone requiring a patent license overprogram?




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Quick Reference For Choosing a Free Software License



Q S


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Quick Reference For Choosing a Free Software License



C i l M i


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Conventional Matrix



M i I l di D l Ch i


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Matrix Including Developers Choice



R k


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Remarks

Some members of the community refuse to accept GPLed source

code into their projects.Other members of the community strongly prefer GPLed sourcecode over other licenses.

Nobody refuses to accept code under permissive licenses such asBSD, X11, MIT...

Almost nobody refuses to accept LGPLed code, except the ApacheFoundation, saying that they think it would impose LGPLrequirement upon the proprietary code (when they are linked via theJava class-loading mechanism).

The FSF disagrees with this statement, asserting that such linkingfalls under section 6 of the LGPLv2 (linking exception).

MPL 1.1 can be specifically amended to allow combining with GPL(section 13).

You should also get your employer (if you work as a programmer) or

school, if any, to sign a copyright disclaimer for the program, ifMiguel Vidal, Gregorio Robles, Jesus M. Gonzalez Barahona Legal Aspects


A l i f li


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Applying a free license

LICENSE or COPYING file.

Copyright and license summary at the beginning of eachsource file.

It should have at least the copyrightnotice and a link to

the full version of the license.Also add information on how to contact you by electronic andpaper mail.

If the program is interactive (terminal), make it output a short

copyright notice when it starts in an interactive mode.If it has GUI, a menu can include copyright notice (or eventhe full license).



E l H t A l th GPL t Y W k


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Example: How to Apply the GPL to Your Work

Copyright (C)

This program is free software: you can redistribute it and/or

modify it under the terms of the GNU General Public License as

published by the Free Software Foundation, either version 3 of

the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

General Public License for more details.

You should have received a copy of the GNU General Public Licensealong with this program. If not, see

.



Example: How to Apply the Apache License to Your Work


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Example: How to Apply the Apache License to Your Work

Copyright [yyyy] [name of copyright owner]

Licensed under the Apache License, Version 2.0 (the License);

you may not use this file except in compliance with the License.

You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,

software distributed under the License is distributed on an AS

IS BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either

express or implied. See the License for the specific language

governing permissions and limitations under the License.



Dual licensing


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Dual-licensing

Distribute software under two different sets of terms andconditions. Motivations:

License compatibility (Perl, Mozilla/Firefox, MySQL).

Market segregation based business models (MySQLEnterprise)

Allows the holder to offer customisations, early releases,generate other derivative works or grant rights to third parties

to redistribute proprietary versions.



Compatibility


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Compatibility

Two licenses are incompatible if it is not possible combiningboth works in compliance with the terms of both licenses atthe same time.

It affects to distribution, not the use.If two licenses are free does, it doesnt imply are compatible.

Copyleft licenses are mutually incompatible, unlesscompatibility is declared explicitly.

Support for linking: even if not allowed mix or integratesoftware with different licenses, maybe it can be linked.



Forking


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Forking

Forks happens when a piece of software is modified and thismodification is developed separately, by another teamdevelopment, and distributed under a different name, andperhaps other license.

The forks can be possible only with free software.

The GPL software has tendency to avoid forking: we mustkeep the original license.

The BSD-style licenses are forked easily.

Forking is considered a bad thing (waste efforts, bitter

disputes...).But there are successful cases: XOrg/XFree86, 386BSD,OpenBSD, Gnu-Emacs/XEmacs, changes of license (GForge,OpenSSH).



Licenses and warranty


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Licenses and warranty

Warranty Disclaimers and limitation of liability clauses arecommon in software.

There are legal doubts about the effectiveness of theseclauses: would not apply to consumers.

This clauses are valid when there is no commercial service.

The proprietary licenses using similar terms: is a myth toaccept greater responsibility.

It must be considered legal guarantees that apply to both

open source and proprietary software.The free licenses allow to add extra warranty clauses.




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Legal Myths




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Free software hasnt owners or

copyright holders




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The free licenses force to grant

copyrights.




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Free software and proprietary

software are incompatible




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Its not possible merge open source

and proprietary software.




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Copyleft licenses force to publish

derivate works.




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Free software dont have neither

warranties nor liability.




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The diversity of free licenses is

positive.


04 Licences

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