Free software is about freedom of speech, not free beer
Free software can cost money and can even be sold for profit. What makes it free, in Richard Stallman's sense, is that anyone who receives it may run it, study it, change it and pass it on. The Free Software Foundation sums it up: think free speech, not free beer.
From the 1950s into the early 1970s, sharing code was simply normal. Programs were usually public domain, and hardware makers welcomed people writing software that made their machines useful; user groups such as SHARE existed to swap it. When that culture shifted, Stallman, a veteran of the hacker community at MIT's Artificial Intelligence Laboratory and one of the original authors of the Emacs editor, announced the GNU Project in 1983 to build a completely non-proprietary Unix-compatible operating system. Development started in January 1984 and the Free Software Foundation was founded in October 1985. Permissive code like the Berkeley Software Distribution of 1978 already existed, but Stallman is credited with giving the term its modern meaning.
The foundation's first formal definition, written by Stallman, appeared in February 1986 and is still maintained. It lists four freedoms numbered from zero, partly as a programmer's joke about zero-based counting. Freedom 3, for example, lets users release improved versions so the whole community benefits. Studying and modifying a program without its source code ranges from impractical to nearly impossible, so the source must be available. Freeware, by contrast, is proprietary software that merely costs nothing, and products such as Photoshop or Windows keep their code closed.
Terminology became a battleground. The phrase open source, coined in 1998, covers nearly the same programs, but the foundation argues it stresses development methods and business appeal while treating user rights lightly. Debian published its own guidelines in 1997. Users of FreeBSD, OpenBSD and NetBSD often find copyleft restrictive and prefer permissive licences that do not force anyone to share source code. The borrowed word libre is often used to dodge the double meaning of free.
Famous examples include the Apache web server, the MySQL database, the GIMP image editor and the GNU Compiler Collection. The approach has spread to microchip designs under copyleft licences and to the Creative Commons and free-culture movements.
Source: Free software
