watching a talk on youtube “Fork Yeah!” about solaris and open sourcing it…. Bryan M. Cantrill from Joyent around this time in the video (1,424 seconds into the video) is discussing license choice and says one of the reasons sun created a new license is that they wanted a file based copy-left license. He likes the file based nature of BSD b/c you can mix and match proprietary code. This file based nature of BSD must be why it is supposed to go on every pages. GPL is a work based copy left — that is why you can’t mix and match with it.