Berkeley Software Distribution o BSD was an operating system derives from the Unix system. It was bornborna from the contributions made to this system by the University of California at Berkeley
GNU is a Unix-like operating system developed by the GNU project. It is composed entirely of free software. Itends to use as GNU Hurd operating system (although its common implementations contain Linux in place, what is called GNU/Linux) and aims to be a "complete software system compatible with Unix". The GNU Project calls GNU operating system in the sense of distribution, very different from receiving Linux or GNU Hurd, using the fformal definitio
The Mozilla Public License (GPL English or MPL) is a licensed open source and free software. It was originally developed by Netscape Communications Corporation (now a division of America Online), and later its control was transferred to the Mozilla Foundation.