sexta-feira, 23 de março de 2007

Licenças livres
- internet distribution instead of mail order

Q7: I'd like to know more about this term "use freely". In patent terminology, to use something freely means that as long as you pay the licence fees, then you can use it.

Richard Stallman: That's not Free Software. In any case, when I informally use terminology like "to use something freely", I am not referring to any country's patent law, and specifically, being free to do something means you don't have to pay for permission to do it. When we describe the four freedoms, when we say that freedom zero is the freedom to run the program as you wish, part of that is: you're not required to pay anyone for permission to run that program as you wish.

And, freedom 2 is the freedom to distribute copies of the program. That means you don't have to pay for permission to do so, you don't have to pay for each copy or negotiate with anybody. You're simply free outright to go and do it.

If there's a program that you're allowed to run only if you pay somebody, that's not Free Software. Therefore, the GNU GPL aims to make sure that nobody can create such a situation. If somebody can create a situation where people feel they must pay in order to be allowed to run a GPL covered program, then that is a flaw, a failing in the GPL and we are doing our best to make sure that can't happen.

I don't believe that all the important ethical issues in life can be modelled on the Free Software movement.
We're not working on open source, we're not interested in open source. By the way, some open source licences are not Free Software licences, the definition of open source came from the definition of Free Software but it followed a circuitous path, and it's written very differently and it's interpreted by different people, so they've drawn the lines in different places, so most of the open source licences are Free Software licences, but there are some licences that the OSI accepted that we consider unacceptably restrictive.
And then are licences that are file-level copylefts. The Mozilla Public License was the first of these. File-level copylefts say "If you modify the files of this program, the modified versions of those same files must be under this same licence". Now, that's not as strong as the GPL. The GPL says if you modify the program, you're whole modified program must be under the GPL. Those file-level copylefts, or we might call them weak copylefts, permit the additional of separate files which are non-free. They don't really achieve the goal of copyleft, but because they made this requirement about the file, it's impossible to relicense that file under the GPL. So the GPL will always be incompatible with those file-level copyleft licences.
The licence of TeX says "You can't modify this file, but you can distribute it with a change file" and then when TeX is built, it's built by patching the standard TeX source code using the change file. So, in effect, you can distribute any modified version in that way, that's how I convinced myself in 1984 that that was a Free Software licence. But if you have two programs under the TeX licence, you can't merge them because each one says: anything that contains this can only be distributed as a changefile from this. So you have two things tugging at each other, each one insisting on being the base. So the TeX licence is incompatible with itself, but it's a Free Software licence.