Gratis versus libre

The English adjective free is commonly used in one of two meanings: "for zero price" (gratis) and "with little or no restriction" (libre). This ambiguity of free can cause issues where the distinction is important, as it often is in dealing with laws concerning the use of information, such as copyright and patents.

The terms gratis and libre may be used to categorise intellectual property, particularly computer programs, according to the licenses and legal restrictions that cover them, in the free software and open source communities, as well as the broader free culture movement. For example, they are used to distinguish freeware (software gratis) from free software (software libre).

Richard Stallman summarised the difference in a slogan: "Think free as in free speech, not free beer."

Gratis in English is adopted from the various Romance and Germanic languages, ultimately descending from the plural ablative and dative form of the first-declension noun grātia in Latin. It means "free of charge", "at zero price", "free", in the sense that some good or service is supplied without need for payment, even though it may have value.

Libre /ˈliːbrə/ in English is adopted from the various Romance languages, ultimately descending from the Latin word lībere; its origin is closely related to liberty. It denotes "the state of being free", as in "liberty" or "having freedom". The Oxford English Dictionary (OED) considers libre to be obsolete, but the word has come back into limited use. Unlike , appears in few English dictionaries, although there is no other English single-word adjective signifying "liberty" exclusively, without also meaning "at no monetary cost".

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