SDSL – Succinct Data Structure Library for C++ (opens in new tab)

Um...is that legal? Nothing in VS is licensed GPLv3.

Also, using GPL for a library is often the better choice!

Many people believe that GPL is for programs and LGPL for libraries - as if the "L" would stand for "Library". But that's wrong! This was never the intention. The "L" stands for "Lesser" and means less protection than GPL, for very special circumstances.

According to FSF, you should use LGPL only for libraries that are competing with widely accepted proprietary libraries. For anything new and original, you should use GPL - to promote Free Software.

"Why you shouldn't use the Lesser GPL for your next library"

https://www.gnu.org/licenses/why-not-lgpl.en.html

(I disagree with that article in one point: If you compete with pervasive software, use a simple license like ISC/MIT/BSD rather than LGPL, to promote their usage even more.)

It would absolutely change. GPL defines any incorporation or usage of a GPL work as a derivative work, thus effectively only permitting other GPL codes to use this library. That means any software in the Apache, Eclipse, or BSD-style ecosystems (among many others) cannot use this.

As for multiple authors, in theory you were required to have their permission to release it under the GPL (or any other open source license) in the first place. Given your uncertainty, it's possible that permission wasn't obtained and you could already be on unstable legal ground. I would reach out to all contributors and ask them for permission to release under a more flexible license like BSD/MIT or Apache2 to encourage more widespread use.

>The library is very template heavy and thus most of the code is in the header files so I guess it wouldn't change much in this case?

Pretty sure the end user is still required to gpl their project if they use your header files.

edit: the more I think about this, the sadder I get. You prevented the majority of people from including your software and it doesn't sound like you meant to do it. Might be worth a rethink in the next version.

I beg to differ. I'm always happy to use external GPL libraries as an excuse for making stuff Open Source. Whenever I talked to unsure customers or managers, this was the single most convincing argument.

Of course, this only works if people aren't strictly against creating Free Software, but in that case you have lost anyway.

Quiet, Richard Stallman might hear you!