Free/libre/open licenses – licenses for works (like software) granting users the four freedoms:

  • freedom to use/run for any purpose;
  • freedom to modify, improve, create derivative works;
  • freedom to publish and pass the work further;
  • freedom to publish and pass further the modified/improved/derivative versions. There are two kinds of such licenses: copyleft and not-copyleft.

Examples: GPL, BSD, MIT (for software); CC-By, CC-By-SA (for other works)

Copyleft licenses – licenses requiring that derivative works (like projects based on a given code/library) are also similarly licensed.

Proponents point out that such licenses are better at protecting and guaranteeing the four freedoms to all possible users of a given code/project/work, by making it impossible for anybody to “close” a derivative work.

Hence, every user of every single derivative work has their four freedoms, regardless of whether they use the original work or any derivative of it.

Examples: GPL license family; CC-By-SA

Non-copyleft licenses – licenses that do not require derivative works to be published on a similar license. Proponents point out that they give more freedoms to direct users of projects using such licenses, as it

allows them even to make a “closed” derivative projects and works. Examples: BSD, MIT; CC-By

Free/libre/open-source software – software licensed under any free/libre/open-source software license. Free/libre/open resources – resources (like sounds, graphics, video) licensed under free/libre/open

licenses for artistic works.

Lists of licenses considered free/libre/open

Open-Source Initiative endorsed licenses:

Free Software Foundation licenses:

Comparison of free/libre/open-source software licenses

Creative Commons free/libre/open licenses for artistic works:

Rider o wolnych licencjach / Free/libre/open licenses rider, autor/by: Michał “rysiek” Woźniak, 2013-2014; na licencji / licensed under: Creative Commons – By attribution – Share-alike – 3.0 PL