Free software is software that gives its users the right to unlimited installation, program startup, free usage, studying, redistribution and modifying. The software is available free of charge, however in some cases it can have a fee.
The name “free software” had been previously used in the Unix world. Not long ago it was accepted in the general computer community. Free software is also called as Freed Software, Liberated Software or freely redistributable software.
In 1983 Richard Stallman set up free software movement. The goal of the given movement was to provide the “software freedom” to computer users. It is noteworthy that the notion itself was introduced by Richard Stallman and it reflects the principles of open software engineering in the scientific community, which was formed in American universities in 1970’s. Richard Stallman formulated the principles of free software. These principles mention authors’ rights, which are transmitted to the computer users:
Freedom 0: the software can be used freely for any purpose;
Freedom 1: freedom to study the way the program operates and adapt it to your purposes, on condition that the incoming text of the program is available;
Freedom 2: you may redistribute the copies of the program freely, to help your neighbors;
Freedom 3: the program may be modified and improved freely. The improvements may be released to the public as well, to profit the whole community.
The main condition of the third freedom is the availability of the incoming text of the program and the possibility to make modifications and corrections in the program.
If the software satisfies the requirements of these four principles, it can be considered free software. Thus it is free and available for modifying and revising.
As opposed to “freeware” which does not have a fee, free software may be redistributed by collecting payment for it, or it can be absolutely free of charge. However, the main thing concerning the software in question is to follow four principles of freedom.
