"The result of this is that proprietary software,

"* does not confirm to good standards for information technology.
* is incompatible with other proprietary software.
* is buggy.
* cannot be fixed.
* costs far more than it is worth.
* can do anything behind your back without you knowing."

http://linuxpoison.blogspot.com/2008/08/why-is-gnu-software-better-than.html