Using, copying and sharing software is permitted under a copyleft license known as the General Public License, which does not require prior consent from the software’s creator. Instead, the software creator or program voluntarily elects to register it under this license, allowing others to use it as they see fit.
On the one hand, copyleft licensing ensure that everyone can continue to use open-source software. Additionally, it prevents someone else from making money off a piece of work that’s made freely available. Advocates for copyleft are frequently more focused on maintaining some level of creative control.
Contrarily, permissive licenses allow for widespread software use as long as the original creators are acknowledged and given credit for their work. Put it another way; a permissive license provides anybody to distribute, modify, and copy work with any form of permission. Again, giving credit to the original creators is the only requirement.
The GPL license is currently the most popular method of sharing free and open-source software. This license governs well-known free software applications, including the GNU Emacs, the GNU Compiler Collection (GCC), and even the Linux kernel.
