A legal instrument/document which governs the use and or redistribution of software.

License Types

Free and Open

Public Domain

Completely waives all copyright protections.

• Creative Commons

Permissive Licenses

Grants use rights, include the right to re license and sell derivatives

• MIT
• Apache
• MPL
• BSD

Copyleft Licenses

Grants use rights, but forbids the ability to sell derivative works.

• GPL
• AGPL

Non-free

Noncommercial Licenses

Grants rights only for non-commercial usage.

• JRL

Proprietary Licenses

The traditional usage of copyright laws. No rights need to be given or granted. All rest with the rights holder

Trade Secret

No information about the product is made public.

Source Available

Grants usage rights but restricts them to certain use cases. This is specifically not free or copyleft software

• SSPL