Software that is not free software or semi-free software (the same thing as free software except that it can only be used for non-profit things).
Windows is an example of proprietary software.
by a thing June 11, 2005
2 more definitions
Proprietary software is software that you are not free to use, copy, modify, and study as you like. It's a form of abuse of users, which sucks and makes people depressed; it gives suits power over creatives.
Skype is extremely proprietary software.
by your real name! June 29, 2009
Something said to be evil, yet nobody knows why.
Software developed by Microsoft is proprietary software, so it's evil.
by Ferreira November 23, 2008