Centos Server Guide

Free software, by definition created by the Free Software Foundation was a computer program that can be used, copied, studied, and redistributed with some restrictions. The freedom of these guidelines is a central concept, which is opposed to the software owner's concept, but not the software that is sold desire for profit (commercial software). The usual method of distribution of free software is accompanied by the free software license, and the inclusion of the source code of programs available.

definition

is considered free when he / she helps to four kinds of freedom for the users of the program defined by the Free Software Foundation:

* freedom to make a program, for any purpose (freedom no. );

* The freedom to study as the program works, and to adapt him / her for your needs (freedom no. 1). I access the source code is a precondition for the freedom,

* freedom of redistribution, in addition to the sale, copies, so you can help his / her close to one (no freedom. );

* freedom to modify the program, and release these changes, so that the whole community benefits (freedom no. 3). I access the source code is a precondition for the freedom,

freedom of execution of the program means the freedom for any kind of a natural person or legal to use the software on as many machines he / she wants, in any type of computacional for any business or activity type, with no restriction imposed by the supplier.

freedom to redistribute a compiled program, which is in binary format, it includes the mandatory nature of making available its source code. In the event that the software comes to be modified and the modifications to the author wants to distribute it / him free or not, it will also be obliged to distribute source code changes because they come to integrate into the program. It is not necessary permission of the author or distributor of the software so that it can be redistributed, as it is free software licenses allow this to him / her.

so it is possible to examine and modify the software (for personal use or for distribution), it is necessary to have access to source code. Therefore, the willingness of these files is a prerequisite for software freedom. Each permit specifies that the supplying source code for a typical distribution, as it is only in the case of distribution in the portable media binary codes concluded (without sources) already. In the event the license GPL, the source should be available at the place where they can access it, or should be given to the user, if requested, at no additional (other than transportation and media) costs.

for those freedoms to be real, they should be irrevocable. In the case of desenvolvedor program has the power to revoke a license, the software is not free.

Most free software licensed under free software, such as the GNU GPL, more an acquaintance.

free software and software in the public domain

Free software differs from software in the public domeni.Prvo, when used in combination with typical (such as licenses GPL and BSD) license, guarantee or authorship desenvolvedor organizacije.Drugi case happens when the passages provided in the laws of any state of copyright and east is becoming very common. However, the software in the public domain can be considered as free software.

free software and copyleft

GPL license contain additional concept known as copyleft, which is based on the expansion of the software without the copyleft prava.Slobodni can include non-free to the user, as is the case to him / her. Even free software is protected by copyleft license that provides, if it is distributed, it should be under the same license, in other words, the law review.

association copyleft free software, and concepts, programs and services carried out free code must be left open (the details of the program, which services and which permissions are defined for the original license application) licence.Korisnika, however, there remains the possibility that there distributed program and maintain the changes or services that are used for himself alone.

Selling Free Software

free software license to allow them to sell, but those in his / her great majority are available for free.

Once the buyer has the right of free software in four striped freedom, he was able to redistribute this software for free or for less cost than you paid.

can cite as an example of Red Hat Enterprise Linux, which is marketed by Red Hat, starting from him, several clones were produced as CentOS, which can be folded away for free.

a lot of companies decide to distribute the same product in two or more licenses, usually once a copyleft license for free as the GPL and another license to the landlady, and he / she pays. Another very common difference is usually paid version to follow some kind of additional services, as well as the right to be supported by a technician, for example.