GCEM license compatibility

[baskanov]

I am not a lawyer and this is not a legal advice, but I'm a bit concerned with the following issue:

GCEM appears to be using Apache License 2.0: https://github.com/kthohr/gcem/blob/master/LICENSE

According to Apache website (https://www.apache.org/legal/resolved.html#category-x), Apache License 2.0 is not compatible with LGPL 2.1 used by FluidSynth.

What do you guys think?

[derselbst]

According to Apache website (https://www.apache.org/legal/resolved.html#category-x), Apache License 2.0 is not compatible with LGPL 2.1 used by FluidSynth.

This is not what it says. It says: "You may NOT include the following licenses within Apache products". That means, that gcem may not distribute a copy of fluidsynth or link to it.

Apache is a permissive license. LGPL is a copyleft license. You can turn a permissive license into a copyleft, but not the other way around.

Additionally, we're not linking against gcem, hence there's not a single trace of gcem source-code or gcem symbol that makes it into the compiled fluidsynth binaries, since it's a pure compile-time dependency.

Because of that, I am not worried at all. I'm not a lawyer either, so what do I know...

[baskanov]

This is not what it says. It says: "You may NOT include the following licenses within Apache products". That means, that gcem may not distribute a copy of fluidsynth or link to it.

Oh, sorry, you are right, it's the wrong document. I can't find any official information on LGPL 2.1 vs Apache 2.0, but here is some on GPL 2.0 which might also be applicable to LGPL 2.1: https://www.gnu.org/licenses/license-list.en.html#apache2

Apache is a permissive license. LGPL is a copyleft license. You can turn a permissive license into a copyleft, but not the other way around.

As I understand, there is an issue with conflicting patent clauses.

Additionally, we're not linking against gcem, hence there's not a single trace of gcem source-code or gcem symbol that makes it into the compiled fluidsynth binaries, since it's a pure compile-time dependency.

OK, this makes sense.