Largely in response to the restrictions and limitations of copyright law, numerous "open" intellectual property (IP) tools have been developed in recent years and are now one of the three main components of the Open Educational Resources (OER).
Of these IP tools, the licenses from the Creative Commons non profit organization have become the most utilized and helpful components for the OER movement. These licenses, which are easy to use and understand for the average person, are also legally solid, and machine readable, which also makes them a natural ally in finding OER. As a result, programmers have constructed Creative Commons(CC) filters for search tools.
GNU General Public License is an example of another "open" software license. It originates from the Free Software Foundation (FSF) that ensures every user receives the essential freedoms that define "free" software, which is free of restrictions (see free software). Also called "GPL" and "GNU GPL," it was created to distribute the software of the GNU operating system (see GNU). Approximately 70% of free software packages are released under this license, including most GNU programs and thousands of others. The GNU General Public License is also considered an open source license (see open source)