From: Caleb Clausen Date: 2009-09-04T09:01:54+09:00 Subject: [ruby-core:25347] Re: [Feature #2032] Change the license to "GPLv2+ or Ruby's original". Gregory Brown wrote: > On Thu, Sep 3, 2009 at 3:29 PM, Bill Kelly wrote: >> Numerous free software licenses are not GPL-compatible. >> >> You stated, the Ruby License "is not considered a free >> software license by the FSF". >> >> That piqued my interest, as I don't understand why the >> Ruby license would not be considered a free software >> license. > > I can try to get another email by the Stallman-to-real-world compiler, > or maybe we could ask the FSF Licensing and Compliance Lab? > > http://www.fsf.org/licensing/ > > I think it is because Matz's terms do not explicitly grant the freedom > to sell the software, even though his terms implicitly say they may be > used for 'possibly commercial' means. The FSF can be pretty > aggressive about their interpretations of things... I suspect that the part which the FSF finds objectionable in ruby's license it this: > 2. You may modify your copy of the software in any way, provided that > you do at least ONE of the following: > > a) place your modifications in the Public Domain or otherwise > make them Freely Available, such as by posting said > modifications to Usenet or an equivalent medium, or by allowing > the author to include your modifications in the software. > > b) use the modified software only within your corporation or > organization. > > c) rename any non-standard executables so the names do not conflict > with standard executables, which must also be provided. > > d) make other distribution arrangements with the author. This places additional requirements on forkers of ruby, which, even tho they are relatively minor, can cause practical problems. Compare, for instance, the traditional BSD license, which was said you can do pretty much anything you like with the source code, provided you give credit to the regents of the university of california. This, and similar clauses in derived licenses (which changed who the credit should go to) eventually caused so many headaches that it had to be rescinded.