Permissive free software licenses

A Permissive software license, sometimes also called BSD-like or BSD-style license, is a FOSS software license with minimal requirements about how the software can be redistributed. Examples include the MIT License, BSD licenses and the Apache license. As of 2016,^[update] the most popular FOSS license is the permissive MIT license.

The Open Source Initiative defines a permissive software license as a "non-copyleft license".GitHub's choosealicense website described the MIT permissive license as, "lets people do anything they want with your code as long as they provide attribution back to you and don’t hold you liable."California Western School of Law's newmediarights.com defined them as follows: "The ‘BSD-like’ licenses such as the BSD, MIT, and Apache licenses are extremely permissive, requiring little more than attributing the original portions of the licensed code to the original developers in your own code and/or documentation.".

Copycenter is a term originally used to explain the modified BSD licence, a permissive free software license. The term was presented by Kirk McKusick, a computer scientist famous for his work on BSD, during one of his speeches at BSDCon 1999. It is a word play on copyright, copyleft and copy center.

The way it was characterized politically, you had copyright, which is what the big companies use to lock everything up; you had copyleft, which is free software's way of making sure they can't lock it up; and then Berkeley had what we called ‘copycenter’, which is ‘take it down to the copy center and make as many copies as you want.’

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