Free as in beerThe expression free as in beer refers to things which are available at no monetary cost (like free beer at a party). It can be contrasted with the expressions free as in speech or free as in freedom, which refer to something which is free of restrictions, as in the freedom of speech.
Since the advent of the free software movement, these terms have entered frequent use, for categorising computer programs according to the licenses and legal fetters which cover them. The expression "free as in freedom" is also the title of a 2002 biography of Richard Stallman, founder of the Free Software Foundation.
To some people (outside the particular context of software), "free beer" can imply free riding, or freeloading taking advantage of something that is not paid for.