> There's a problem in the software development world, a practice that breaks down the free and open exchange of information. [...] I'm talking, of course, about copyleft licenses such as the GPL.

It takes some spectacular mental gymnastics to believe that requiring available source code hinders "open exchange of information".

> The GNU General Public License (GPL) is the most well-known example of a so-called "copyleft" license and it requires, among other things, that any project which utilizes GPL code that is released must, itself, be released under the GPL.

No, the GPL requires that anything dependent on GPL code must be under a compatible license. You're free to release code under the BSD or X11 or zlib or apache (etc...) license. The author is just repeating the same tired old propaganda that's been shoveled out by proprietary software vendors for years.

> I've never built an open-source project so large or complex that someone else, given a little time and elbow grease, couldn't work out a similar solution in a reasonable amount of time.

Most interesting opinions come from experience. If the author has never built anything significant, perhaps they ought to stop and consider where their opinions come from.

> So how do I get people to contribute? It isn't going to be by using the GPL...people will say "screw it" and build their own version of my library that they can use without worrying about overly cumbersome licenses. [...] No, I get people to contribute by giving it away as completely as possible (I use the MIT license, but also like the WTFPL) and asking them to contribute interesting stuff back.

This assumes that the same people contributing code would refuse to do so if the project was GPL-licensed, which to me seems extremely unlikely. I have released software under several licenses (including GPLv2, GPLv3, X11, and BSD-3); every single person who has begged me to change from the GPL to a proprietary-friendly license has never contributed a patch. Not a single bug fix, nor test case, nor even benchmark. Every contribution I've received, large or small, has been from people who are themselves working on open-source software.

> Copyleft licenses are simply not necessary for the vibrancy of the open-source community when it comes to simple libraries and, in fact, are more likely to hinder the community by encouraging the creation of multiple libraries to accomplish the same thing simply to avoid the requirements of a license like the GPL.

Does any HN reader have a case where a member of the "open-source community" was harmed, hindered, or even momentarily annoyed by having to use GPL'd software? Because I can't think of any case, nor any reason why one might occur.

> The Affero GPL is a variant of the GPL specifically designed to address software that runs on network servers (such as web applications). It requires that any server running the software (or a modified version thereof) must make available the full source code of any modifications.

This is also wrong. The AGPL is, like the GPL, a copyright license. It only applies if the remote application (or derived data) is itself being sent to a client. For example, if I let an AGPL'd httpd serve my files, I am under no obligation to do anything at all regarding its source code.