Free Software Foundation
Free Software Foundation (FSF) is a non-profit organization founded in 1985 by communist agitator Richard Stallman to support the free software movement.
Free as in...
By "free," Stallman refers not only to free speech, in that free software is retarded and un-American, but also to free beer, since free software is full of cigarette butts and is an excellent way to reduce hobos' genetically-inherited resistance to fire.
The FSF is notoriously difficult to deal with, being full of dirty hippies and communists who refuse to let little things like practicality or showers compromise their ideals. Instead of working cooperatively with large corporations to find a common ground, the FSF has been known to pull shit like rejecting software that met all their requirements of being free, but that was initially compiled with a commercial IDE or came in contact at any point with something that might have cost money, as if paid software were like peanuts to someone with a nut allergy. Their insistence that all software should be free makes them a laughing-stock of the computer world; even many open-source advocates find their standards so extreme as to be laughable.
How to work with the FSF
Don't. You can't.
If you plan on writing "free software" and are not in any way affiliated with Stallman or the FSF, just forget about it. They will nitpick everything you do, and make up new arbitrary rules so that all the idiots who do anything Stallman says (if you program for Linux, this means just about everybody) will not use it.
Indeed, the FSF will not be happy until everyone is forced to turn to the FSF for all of their software needs! Why else would nearly all the programs that meet their expectations be directly affiliated with them in some way?
Then the FSF will have a monopoly in everything computer, it will rule the universe! AHAHAHAHAHAHAHAHAHAHAHA!!!!!!!PROFIT!!!!11!!