Licenses A Legal Necessity Copyright © 2015 – Curt Hill

Preamble As a user of software you have been required to accept a license agreement –Many times As a developer of software you will need to know what sort of license you will use –Provided you distribute your creation

Licenses A binding agreement between two parties, that is a contract Usually about an item that one of the parties has created and the other intends to use It specifies what each party may and may not do –It grants rights and limits actions to each of the parties –It also dictates liabilities Copyright © 2015 – Curt Hill

Software Copyright Software is subject to copyright laws as well –All software not in public domain is copyright Copyright © 2015 – Curt Hill

Several kinds Only interested in the kinds of licenses relevant to software These include: –Public domain –Two GPLs –MIT –BSD –Proprietary –Among many others Each of these protects the rights of the licensee or licenser to various degrees Copyright © 2015 – Curt Hill

Public Domain The non-license Material in the public domain has no restrictions –It belongs to everyone Most documents/software/processes produced by the U. S. Government are in the public domain Anyone may use and then modify Copyright © 2015 – Curt Hill

Derivative Works A person may take something in the public domain and modify it They may then apply any license they choose to the resulting work –However, this only effects the new item, the original is still in the public domain In general this true for any derivative work –The modifications and original may have completely different licenses Copyright © 2015 – Curt Hill

Proprietary The opposite of public domain Each one is different but they typically have several common features: –Ownership is reserved to developing company –The product may not be sold or given to anyone else –Number of machines and copies is strictly limited –May not be modified, disassembled, reverse engineered etc. Copyright © 2015 – Curt Hill

Free Software Foundation Sponsor of GNU and the GPL licenses Mission is to: … preserve, protect and promote the freedom to use, study, copy, modify and redistribute computer software, and to defend the rights of free software users Started in 1984 Copyright © 2015 – Curt Hill

GNU Originally to promote and develop free UNIX like operating sytems –BSD and LINUX derivatives –UNIX developed by Bell Labs One of their goals is to keep the software free –Consequence of the UNIX story Name is now a recursive acronym GNU’s Not UNIX Copyright © 2015 – Curt Hill

Problems Many projects had started with public domain or other free software and applied modifications These were then licensed with a proprietary style license This is not illegal, but is it immoral? –The extreme case is take a complex software make a small modification, then sell with a proprietary license Thus, the advent of copyleft in the GPL Copyright © 2015 – Curt Hill

Freedom GNU believes in four freedoms –Use software for any purpose –Change the software in any way –Share the software –Share your changes to the software This is what constitutes free software to GNU –Contrast this with free apps on smart phones Unlike most licenses it preserves future deriver’s rights and freedoms Copyright © 2015 – Curt Hill

General Public License The software must remain free –Including software that uses it The source must be available even if not universally distributed with the object or executable –Does not require distribution of the object or executable, but if it is the source must be available The most unusual stipulation is that no license more restrictive than the GPL can be applied to derivative works Copyright © 2015 – Curt Hill

GNU Lesser Public License Solves a problem with the GPL: –GPL covered code cannot be mixed with any more restrictive license –The entire software must be free The Lesser license allows the software to be used with more restrictive licenses –Typically used with libraries that have general use or programs that use libraries with more restrictive license –The software itself is still free in the GNU sense Copyright © 2015 – Curt Hill

Example Suppose I write a program that does something I will use GPL covered libraries I cannot donate this to the public domain because of GPL –Nor should I use anything but the GPL –This still protects my intellectual property rights from being exploited by someone else If I choose a library without copyleft then I should choose the Lesser GPL Copyright © 2015 – Curt Hill

BSD Licenses Berkely Software Distribution use their own license It allows use, modification, redistribution It originally required notification that the original copyright holder is the Regents of the University of California –This notice had to be maintained in advertising as well –This clause was later removed Not a copyleft form, but not very restrictive Copyright © 2015 – Curt Hill

MIT Licenses Similar to BSD, a series of licenses Prohibits using MIT’s name or copyright in advertising Also not a copyleft –A derived product can be proprietarily licensed Copyright © 2015 – Curt Hill

Observations Wikipedia lists 43 free and open source licenses Each of these has a different set of terms In our case we need to be aware of the terms since we will start with an existing software package and make modifications Since not everything is free software we need to be aware of what we can and cannot do Copyright © 2015 – Curt Hill

Assignment We will now examine the End User License Agreement, which is at: nts/minecraft_eula nts/minecraft_eula You are to prepare a one page executive summary that answers: –What you can do? –What you cannot do? –Penalties for breaking the terms? –How does this compare with other EULAs? Copyright © 2015 – Curt Hill