The term “free software” is sometimes misunderstood—it has nothing to do with price. It is about freedom. Here, therefore, is the definition of free software: a program is free software, for you, a particular user, if:
- Freedom-0:
You have the freedom to execute the program, the way you want and to serve any kind of purpose. - Freedom-1:
You have the freedom to study how the program works and you are free to modify the program to suit your needs - Freedom-2:
You have the freedom to redistribute copies, either gratis or for a fee. So that you can help others and also you can earn profit too. - Freedom-3:
You have the freedom to distribute modified versions of the program, so that the community can benefit from your improvements.
Examples:
The Free Software Directory maintains a large database of free-software packages. Some of the best-known examples include the Linux kernel, the BSD and Linux operating systems, the GNU Compiler Collection and C library; the MySQL relational database; the Apache web server; and the Sendmail mail transport agent.