Jeronimo, mruby is not ruby itself, but also created by Matsumoto. https://github.com/mruby/mruby I see this is under MIT.
How it was possible ? November 21, 2020 2:15 PM, "Jeronimo Pellegrini" <j...@aleph0.info> wrote: > "Mike" <tankf33...@disroot.org> writes: > >> hi all, >> >>> at yesterday's PilCon it turned out that pil21 has a serious licence >>> problem. >> >> We already discussed this pseudo problem with Alex in Delta Chat thread. >> If I understand now correctly this is not a problem and Pil21 should keep >> using readline GPL >> library and be covered by MIT/X11 licence. > > As I understand, this is exactly what the GPL was intended to not let > happen. And this is what led CLISP to be licensed under the GPL long > time ago: > > https://gitlab.com/gnu-clisp/clisp/-/blob/master/doc/Why-CLISP-is-under-GPL > > Haible, in his last email in that thread, mentions that > > I had to put CLISP under GPL because libreadline.a was something I wanted > to use and I didn't want to write myself. libgmp.a is similar in this > respect, and it may therefore help putting some new packages under GPL. > > Building libgmp.a was just too hard work. Other people shouldn't get it for > free. > >> 1. >> Lets take a real world example, get all packages of ArchLinux required by >> readline, "Required By >> (133)" on the right: >> https://www.archlinux.org/packages/core/x86_64/readline >> >> https://www.archlinux.org/packages/community/x86_64/mruby >> Mruby, ruby's official mini implementation from Mr. Matsumoto covered by MIT >> licence and have >> readline as dependency. >> I assume Matsumoto knows everything about licences. > > I'm not sure what happens with Ruby; there seems to be a "GPL" file in > their repository, but the "COPYING" file only mentions the Ruby > license and the BSD license. > > https://github.com/ruby/ruby/blob/master/COPYING > https://github.com/ruby/ruby/blob/master/GPL > > The "LEGAL" file, which would list all used software and their licenses > do not mention readline. > > https://github.com/ruby/ruby/blob/master/LEGAL > > Ruby used to be licensed under GPLv2 also, but they dropped it. > readline switched from GPLv2 to GPLv3 in version 6. > > Anyway -- see below about the meaning of a license being compatible > with the GNU GPL. > >> 2. Wikipedia text for MIT says: "... The MIT license is compatible >> with many copyleft licenses, such as the GNU General Public License >> (GPL); ..." > > Compatible means you can use them together. Butif you do, the resulting > software needs to be licensed under the GPL. From the GPL, section 5(c): > > c) You must license the entire work, as a whole, under this License to > anyone who comes into possession of a copy. This License will therefore > apply, along with any applicable section 7 additional terms, to the > whole of the work, and all its parts, regardless of how they are > packaged. This License gives no permission to license the work in any > other way, but it does not invalidate such permission if you have > separately received it. > > So you'd need to license the entire work, as a whole, under the GPL. > > From the MIT license: > > Permission is hereby granted, free of charge, to any person obtaining a > copy of this software and associated documentation files (the > "Software"), to deal in the Software without restriction, including > without limitation the rights to use, copy, modify, merge, publish, > distribute, sublicense, > > "Sublicense" -- it allows you to relicense the work under a different > license. > > From RMS/FSF (https://www.gnu.org/licenses/license-compatibility.html): > > By the same token, lax licenses are usually compatible with any copyleft > license. In the combined program, the parts that came in under lax > licenses still carry them, and the combined program as a whole carries > the copyleft license. > > Also (https://www.gnu.org/licenses/gpl-faq.html#IfLibraryIsGPL), > > The software modules that link with the library may be under various GPL > compatible licenses, but the work as a whole must be licensed under the > GPL > > J. -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
