1. Open Source Software Licenses
Lindsey Young

2. 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.

3. 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

4. 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?

5. Usage ranks

6. 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.

7. 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

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

9. 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.

10. This is here so I can mention WTFPL
DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE Version 2, December Copyright (C) 2004 Sam Hocevar 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 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.

11. Not clear enough?

12. 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.

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

14. References
Berne Convention. Web. 23 Apr <
Black Duck Software. “Top 20 Open Source Licenses” Web. 23 Apr <
Bridy, Annemarie. “The Digital Death of Copyright's First Sale Doctrine” Freedom To Tinker. 10 Oct Web. 23 Apr <
Coleman, Martin A. "Freedom From Restriction, Freedom Of A Restriction: A Comparison Of Some Open Source Software Licenses." Cornell University Library. 10 Feb Web. 23 Apr <
Open Source Initiative. “Open Source Licenses” Web. 23 Apr <
Rumpe, Bernhard, and Carsten Kolassa. "The Influence of the Generator's License on Generated Artifacts." Cornell University Library. 9 Dec Web. 23 Apr <
tl;dr Legal. “Apache License 2.0” Web. 23 Apr <
Walli, Stephen R. “Which open source software license should I use?” Open Source Initiative. 29 Jan <
Wikipedia. “Copyleft” Web. 23 Apr <
Wikipedia. “Permissive free software licence” Web. 23 Apr <
Wikipedia. “Tivoization” Web. 23 Apr <
WTFPL. Web. 23 Apr <