From: Yusuke ENDOH Date: 2010-06-17T04:25:02+09:00 Subject: [ruby-core:30782] Re: [Feature #2032] Change the license to "GPLv2+ or Ruby's original". Hi, 2010/6/16 mathew : > However, I haven't seen a FSF statement as to whether distributing GPL2 code that links with GPL3 code is a violation. http://www.gnu.org/licenses/gpl-faq.html#v2v3Compatibility > Is GPLv3 compatible with GPLv2? > > No. Some of the requirements in GPLv3, such as the requirement > to provide Installation Information, do not exist in GPLv2. As > a result, the licenses are not compatible: if you tried to > combine code released under both these licenses, you would > violate section 6 of GPLv2. > My take is that so long as the code is written to be linked with readline5 and only tested and supported with readline5, that's what it's a derivative of. Just state that clearly where the list of required libraries is in the documentation,. > > If the developers of readline6 have made that library compatible enough with earlier versions that it can be used as a substitute, that's up to them, but you're only required to fall under the same license as the library you're intentionally using. You can't be held to a new license just because someone decides to substitute readline5 with something else that's API-compatible but has a new license. I entirely agree with you. We have no legal responsibility to care readline6, I believe. However, some people (including Matz [ruby-dev:39178] and Shyouhei Urabe [ruby-core:30652]) think that it is "dishonest" to get along with the status quo after we found out about readline6. I don't deny that we have "moral" responsibility about readline6. But now, I'm not sure if the note about readline6 really complies with Ruby License, especially the section 6 of GPLv2: > You may not impose any further restrictions on the recipients' exercise of the rights granted herein. The note restricts the link with readline6. Isn't it "any further restrictions"? I don't know. Shyouhei, let me ask your opinion. -- Yusuke Endoh