[justin66]

>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.

[amelius]

In spite of its good intentions, a restrictive license such as the GPL is always a weakness and a flaw. I would like to pose the conjecture that any library with a GPL license will eventually be replaced by a library with a more liberal license; the reason is simply because it has one feature extra, which is the more liberal license.

[vog]

> any library with a GPL license will eventually be replaced with a library with a more liberal license

That's probably true, but it is not an argument against using the GPL.

If your GPL library is original and useful, the cost of reimplementing it will probably higher than the cost of making some depending piece of software Open Source.

So during the time until somebody else wrote that ISC/MIT/BSD version (which may be decades, think of GCC versus clang!), lots of other software may have been made Free Software that would otherwise have been proprietary.

[brlcad]

I love open source and appreciate free software tenants, but think this is absolutely an argument against using the GPL for library-style codes.

Your point is an ancillary benefit. Most authors don't publish libraries to encourage the greater FSF-ecosystem or free software agenda -- they publish to make it available to others and see it get put to use. Picking a license that limits prevalence of use is contrary to that objective, plain and simple.

It also does not necessarily follow that proprietary would have been the alternative to free software. Published as ISC/MIT/BSD, lots of additional open source software would have been able to make use of the library, advanced more quickly, more easily permitted additional open source and free software derivatives, etc.

More power to authors that choose to use GPL on a library code, as they are certainly entitled to do so, but it is a substantially limiting factor in the near and long term. We do not have to agree on these points. ;)

[jeffreyrogers]

gcc vs. clang is probably a special case. Code compiled with gcc doesn't become GPL, which is part of why it is so popular.

[jheriko]

yeah, projects under LGPL (e.g. Qt) include a special modification allowing use of header files so that people can actually use them as pre-built libraries due to the famously confusing 'static linking' statements in the licenses.

from what I understand even LGPL doesn't allow you to use header files in non (L)GPL code in order to interoperate with an LGPL library.