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Home , Copyleft, Copyright

Open Source, , http://www.gnu.org/copyleft/

 To copyleft a program, we first state that it is copyrighted; then we add distribution terms, which are a legal instrument that gives everyone the rights to use, modify, and redistribute the program's code or any program derived from it but only if the distribution terms are unchanged. Thus, the code and the freedoms become legally inseparable.

 Proprietary developers use copyright to take away the users' freedom; we use copyright to guarantee their freedom. That's why we reverse the name, changing “copyright” into “copyleft.”

CPS 82, Fall 2008 12.1 CPS 82, Fall 2008 12.2

Open Source, www.opensource.org Open Source

1. Free Redistribution: can’t force, can’t prevent sale  Copyleft licenses compared to free licenses 2. : must be available, cheap or free  Copyleft is “viral”, requires redistribution to be 3. to modify, redistribution with same terms the same or similar 4. Integrity of ’s source (patchable, versioning)  Free licenses have no downstream restrictions 5. No discrimination against persons or groups 6. No discrimination against fields of endeavor  GPL is the Gnu Public License 7. Distribution “no strings”, no further licensing  Currently v3, which is a complex, legal license 8. License not bound to whole, part redistribution ok  X11 or BSD or Apache 9. No further restrictions, e.g., cannot require open  All are free/open, but not viral, e.g., may permit commercial or proprietary products 10. Technology neutral

CPS 82, Fall 2008 12.3 CPS 82, Fall 2008 12.4 LGPL: Lesser (nee Library) GPL Freedom

developers, seeking to deny  But we should not listen to these temptations, the free competition an important advantage, will because we can achieve much more if we stand try to convince not to contribute libraries to together. We developers should the GPL-covered collection. For example, they may support one another. By releasing libraries that are appeal to the ego, promising “more users for this limited to free software only, we can help each library” if we let them use the code in proprietary other's free software packages outdo the software products. Popularity is tempting, and it is proprietary alternatives. The whole free software easy for a library developer to rationalize the movement will have more popularity, because free that boosting the popularity of that one library is software as a whole will stack up better against the what the community needs above all. competition.  http://www.youtube.com/watch?v=WLrrBs8JBQo  http://www.youtube.com/watch?v=0HYuv0Q7sdQ

CPS 82, Fall 2008 12.5 CPS 82, Fall 2008 12.6

One program, two licenses License and Royalty

 If you want to distribute an open source/free project  http://mp3licensing.com/royalty/  We’ll license the code to you without payment  Why is mp3 subject to licensing?  100 Million euros in 2005 ()  If you want to distribute or use code commercially  grants license  You can pay for a different license  Why isn’t this a copyright issue?  Are other products sold with different licenses?  What is copyrightable?  Volume licensing  What is patentable?  Others?

CPS 82, Fall 2008 12.7 CPS 82, Fall 2008 12.8