Sometime on Apr 15, nipra assembled some asciibets to say:
proprietary means owned by someone. All free software is owned by the copyright holders. Only public domain software is not owned.
Proprietory software means owned by someone with owner exercising control over it by means of putting up restrictions on use, redistribution or modification of software and thus eventually making it non-free.
So are you saying that the GPL enforces no restrictions on the use, redistribution and modification of the software? Let me go over this.
Free to use without restriction - okay Free to redistribute without restriction - sort of okay Free to modify without restriction - nope
You are free to modify if and only if you either do not redistribute your modified version, or you release your modified version under the same terms.
This is a restriction on modification, and is only possible if you actually own the software, ie, the software is proprietary (note the spelling. proprietory is not a word).
"The Collaborative International Dictionary of English v.0.48" Proprietary Pro*pri"e*ta*ry, a. L. proprietarius. Belonging, or pertaining, to a proprietor; considered as property; owned; as, proprietary medicine. 1913 Webster