What is free software?

Free software, as defined by the Free Software Foundation, is software which can be used, copied, studied, modified and redistributed with little or no restriction. This is distinguished from proprietary software. This definition of free software, as used by the Free Software Foundation and others in the free software movement, does not depend on whether a fee is charged for the distribution of the software.

The usual way for software to be distributed as free software is for the software to be licensed to the recipient with a free software license (or be in the public domain), and the source code of the software to be made available (for a compiled language).

By contrast, "Freeware" is software made available free of charge, but it may be proprietary, as users do not necessarily have the freedom to copy, study, modify or redistribute it. Source code for freeware may or may not be published, and permission to distribute modified versions may or may not be granted.

Free software is entirely compatible with commercial software: a prohibition on selling the software would be a restriction failing the free software definition. Although the ability of the community to use and distribute the software at no cost can make it difficult to sell the software at a profit, funding models exist to give everyone the freedom to charge for distributing, modifying or any other work performed with free software.