What Is the GNU Public License?
The most important thing to emerge from the GNU project has been the GNU General Public
License (GPL). This license explicitly states that the software being released is free, and that
no one can ever take away these freedoms. It is acceptable to take the software and resell it,
even for a profit; however, in this resale, the seller must release the full source code, including any changes. Because the resold package remains under the GPL, the package can be distributed free and resold yet again by anyone else for a profit. Of primary importance is the liability clause: The programmers are not liable for any damages caused by their software. More about GNU and the GPL can be found at http://www.gnu.org.
It should be noted that the GPL is not the only license used by free software developers
(although it is arguably the most popular). Other licenses, such as BSD and Apache, have
similar liability clauses but differ in terms of their redistribution. For instance, the BSD license
allows people to make changes to the code and ship those changes without having to disclose
the added code. (The GPL would require that the added code be shipped.) For more information about other open-source licenses, check out http://www.opensource.org.
The most important thing to emerge from the GNU project has been the GNU General Public
License (GPL). This license explicitly states that the software being released is free, and that
no one can ever take away these freedoms. It is acceptable to take the software and resell it,
even for a profit; however, in this resale, the seller must release the full source code, including any changes. Because the resold package remains under the GPL, the package can be distributed free and resold yet again by anyone else for a profit. Of primary importance is the liability clause: The programmers are not liable for any damages caused by their software. More about GNU and the GPL can be found at http://www.gnu.org.
It should be noted that the GPL is not the only license used by free software developers
(although it is arguably the most popular). Other licenses, such as BSD and Apache, have
similar liability clauses but differ in terms of their redistribution. For instance, the BSD license
allows people to make changes to the code and ship those changes without having to disclose
the added code. (The GPL would require that the added code be shipped.) For more information about other open-source licenses, check out http://www.opensource.org.
