Can I include a modified GPL/Apache licensed font in my LGPL project?

Question

I want to include a GPL & Apache duel-licensed font in my LGPL project, but didn't really find a clue if that's possible.

There are two problems here:

1. I didn't find any clue about Apache license's "LGPL Compatibilty". I know both the licenses involved here are compatible with GPL, but I still prefer to release the work under LGPL.

2. It's kind of tricky since it's a font. It was GPL & Apache duel-licensed, but the LGPL terms are asking about "Library", its "Public API", "Linking" or something. I am not really sure what the operation belongs to if I just edit a .ttf file manually, not even sure about if that's counted as "source".

Any help would be really appreciated!

Answer 1

Let's get some basics in discussed:

SO what's a license really? A license is essentially a set of permissions with a set of conditions. A licence allows you do things provided you adhere to certain other conditions; this in turn also implies things you can't do! For example in a commercial licenses you can use but can't distribute. In GPL you can use, modify as well as distribute but can't prevent anyone else from distributing. In fact GPL licence GPL software can't be distributed with lesser strict license i.e. it doesn't allow you publish the same software which in turn can be taken up and re-dsitributed with non-GPL licences (or any commercial licence).

SO what does a compatible licence means?
A set of license can be called compatible if terms of one doesn't contradict with other. You can think of LGPL as a pure subset GPL. i.e if you distribute the modified version of the work as source code everything mandatory as LGPL is just the same as GPL. But if you are only using some library in binary form conditions are much more relaxed. Hence it is compatible licenses. Typically one can convert it from one way to other but not vice-versa. Incidently, MIT and Apache license are much more relaxed - unlike GPL/LGPL.

SO what happens when you have two license for the same software?
Basically, a license is a choice you make to use as well as comply. Given that you have 2 license, you have 2 choices. You can choose which one applies to your case. And that's perfectly valid legally. (DISCLIAMER: I AM NOT LAWYER). So for example if a code is available under LGPL to me, which allows me to publish my code linking with it as binary only - it is perfectly legal to do so. Now even if the same code is also distributed under GPL it doesn't matter because LGPL permissions are equally available to. Of course nothing prevents me to assume GPL conditions and permissions either; but usually whichever license works for you, you can choose.

SO why would one have dual license anyway?
If in any case, lesser of the two license is going to be applied - what's the point of the second one? A classic case is QT and other such open source yet commercial outfits. The catch is, if you pay QT - you can acquire LGPL for QT and then it can allow you to distribute your binary. However, LGPL is not available for general public - there only the more stringent GPL applies. Hence, it is also critical to note who is granted what license!

So now about your particular question:

1. If the font you are using was GPL (only) licenced - there is no choice but your own code has be to released under GPL. (Or of course drop that font). It can't be released.

2. If the font you are using was Apache (only) licensed - the only condition is the Warranty Disclaimer and Credits being granted to the original developer. In this case, you can release your code under Apache license, LGPL, GPL and even commercial license.

3. Since there are two licenses available, you can choose which one applies! That's it. Of course, you must validate that Apache license is applicable to you.

Hope this gives you clarity you were seeking.