>>67
What?
software isn't proprietary just because it comes without source code. people modify software all the time without source code
It takes an unnessary amount of effort to make meaningful changes to binary code. Users need source code in order to practise freedom 1 in a meaningful way.
Proprietary software is non-free by virtue of not granting enough rights to practise all four essential freedoms.
>>69
Think of two independantly developed and functinally comparative programs. One of these programs are free software licensed under the GPL and the other one under a non-GPL free licence.