Open Source Software Licenses Lindsey Young

Why do I care? 85-98% of all enterprises use open source software 76% of developers have used open source technology for work Simply giving software away on no terms is a liability.

Basic copyright law Berne Convention Fair use First sale doctrine Private creations automatically copyrighted Addition of a copyright clause strengthens claim Fair use First sale doctrine You buy it, you can do what you want Software is selling licenses, not software being purchased

Why do it? Do you want to collaborate with people globally? Are you looking for help with the code? Can you not provide support alone? Do you want your software to transparent for the consumer? Are you looking for the legal protections these licenses offer?

Usage ranks

The GNU GPL v2 Benefits use commercially modify and redistribute add warranties author has no liability Drawbacks must include original unmodified relicense with GPL v2 v3 Ditto except: Licensed software on an embedded system with mandatory security means the security system’s source has to be released. LGPL is basically v3 specifically for libraries in use by nonfree software.

BSD licenses 3-clause - “New”/”Revised” Older version of the 2-clause Additionally requires that the copyright holder and contributors cannot be used endorse a product without explicit consent. 2-clause - “Simplified”/”FreeBSD” Benefits use commercially modify and redistribute add warranties author has no liability relicense with similar reqs Drawbacks must include license unmodified mention original author

MIT Basically the same as the 2-clause Simpler language No redundancy

Apache Essentially the same as MIT or BSD 2-clause, except: NOTICES file must always be included with the software if you use it. Example use (Apache httpd-2.0): mention other open source software used in software tell users there is encryption where software was developed If you change the software you need to explicitly state your changes.

This is here so I can mention WTFPL DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE Version 2, December 2004 Copyright (C) 2004 Sam Hocevar <sam@hocevar.net> Everyone is permitted to copy and distribute verbatim or modified copies of this license document, and changing it is allowed as long as the name is changed. DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 0. You just DO WHAT THE FUCK YOU WANT TO. Microsoft Public License Basically MIT or BSD 2-clause, but made by Microsoft. Source code is different from binaries. Compiled - can use other licenses. Source - must use Microsoft PL.

Not clear enough?

Copyleft and permissiveness Do what you want, but you know where you got it. Copyleft If you do what you want everything you do has to let everyone else do what they want always and forever.

So many more choices Mozilla Public License Eclipse Public License Artistic License (Perl) PHP License Python License

References Berne Convention. Web. 23 Apr. 2015. <http://zvon.org/law/r/bern.html#p~6> Black Duck Software. “Top 20 Open Source Licenses” Web. 23 Apr. 2015. <https://www.blackducksoftware.com/resources/data/top-20-open-source-licenses> Bridy, Annemarie. “The Digital Death of Copyright's First Sale Doctrine” Freedom To Tinker. 10 Oct. 2011. Web. 23 Apr. 2015. <https://freedom-to-tinker.com/blog/abridy/digital-death-copyrights-first-sale-doctrine/> Coleman, Martin A. "Freedom From Restriction, Freedom Of A Restriction: A Comparison Of Some Open Source Software Licenses." Cornell University Library. 10 Feb. 2014. Web. 23 Apr. 2015. <http://arxiv.org/abs/1402.2079>. Open Source Initiative. “Open Source Licenses” Web. 23 Apr. 2015. <http://opensource.org/licenses> Rumpe, Bernhard, and Carsten Kolassa. "The Influence of the Generator's License on Generated Artifacts." Cornell University Library. 9 Dec. 2014. Web. 23 Apr. 2015. <http://arxiv.org/abs/1412.2963> tl;dr Legal. “Apache License 2.0” Web. 23 Apr. 2015. <https://tldrlegal.com/license/apache-license-2.0-%28apache-2.0%29>. Walli, Stephen R. “Which open source software license should I use?” Open Source Initiative. 29 Jan. 2013 <http://opensource.com/law/13/1/which-open-source-software-license-should-i-use> Wikipedia. “Copyleft” Web. 23 Apr. 2015. <http://en.wikipedia.org/wiki/Copyleft> Wikipedia. “Permissive free software licence” Web. 23 Apr. 2015. <http://en.wikipedia.org/wiki/Permissive_free_software_licence> Wikipedia. “Tivoization” Web. 23 Apr. 2015. <http://en.wikipedia.org/wiki/Tivoization> WTFPL. Web. 23 Apr. 2015. <http://www.wtfpl.net/txt/copying/>