Using the term “permissive” as an antonym to “copyleft” – or “restrictive” as its synonym – are unhelpful framing. Describe license reciprocity instead.
Some open source licenses implement a clever hack invented by Richard Stallman where, as a condition of the copyright license, anyone creating derived versions has to agree they will license the new version the same way as the original. In a play on words, this concept is called “copyleft” and many open source licenses implement this hack. Continue reading
Perhaps you didn’t spot it, but last month in their new Berkeley DB release Oracle changed the license associated with the software. Many will see this as a betrayal of trust, despite the fact that the new license (the AGPL) is also strongly copyleft, published by the FSF and approved by the Open Source Initiative. Of course, Oracle are completely within their rights to change the license as they see fit, but for Web developers using Berkeley DB for local storage, the seemingly small change from one strong copyleft license to another may well be seen as cynical and manipulative.
Why would that be? Continue reading