First developed in the 1970s, BSD and its contemporary offspring all use variations of an open source license that is short, simple, and generally GPL compatible, yet still allows proprietary products to be built and sold from BSD code without requiring that the source code be given away.
Unlike the GPL, which arose from one person’s set of beliefs about software, the motivation behind the original “Berkeley license" had to do with the fact that taxpayer money was used to fund the research at a public university. The Berkeley license was thus designed to make that original work available to all. The three main flavors of BSD today are still licensed under variations of the original license. All of these include:
A copyright notice
A disclaimer of warranty
A brief set of conditions, stating that redistributions of the source code and/or compiled code must contain the following:
The copyright notice
This list of conditions
And that, generally, is it.
BSD is considered a very permissive license, much more so than the GPL. Its terms allow for the unrestrained borrowing of source code for other software projects or commercialized versions of BSD itself, with no provision for the sharing of source code, modified or not. This has to do with the software’s public university origins—because taxpayers had funded the project, it was believed that any U.S. citizen should be allowed to do what they wanted with it.
Apple proudly incorporated ...