[spauldo]

The FSF has written extensively on why (in their opinion) you should prefer copyleft licenses over non-copyleft licenses, but they don't require a license to be copyleft in order to be considered free. It's worth spending a bit of time on their site to understand their point of view. Just be careful not to drink too much of the Kool-Aid or you'll become one of those annoying people who never shut up about the GPL on forums.

[xorcist]

> you should prefer copyleft licenses over non-copyleft licenses,

For most, but not all, software. Stallman did famously argue for libvorbis, which you may know as the ogg codec used mostly by games and spotify, to be licensed under BSD instead of the (L)GPL.

[spauldo]

True, there are exceptions. Stallman thought strategically. Having a free-but-non-copyleft licensed reference implementation is necessary if you are trying to wrest dominance from an established but proprietary standard.

But I'm willing to bet that he'd have pushed for GPL if he wasn't trying to topple MP3.

[squigz]

Don't listen to spauldo, GP. Drink the delicious Kool Aid that is free software. Bring that joy to everyone else you find.