BSD License

FreeBSD is released under an open source license, the BSD License. This license is very liberal and allows developers to practically do anything with it they want. The BSD license is less restrictive than the GNU General Public License (GPL) on which Linux is based, but more restrictive than the Public Domain.

Developers are free to modify, copy and redistribute BSD licensed software in either source or binary form, and are not required to donate any changed code or patches back to the upstream BSD-licensed software. Developers are free to change the license, or charge for derivatives of the software, be it commercial or proprietary. Yes, that's right, software released under the BSD license may be incorporated into closed source commercial products. Work based on the material may even be released under a proprietary license.

Some notable examples of this are the use of BSD networking code in Microsoft products and the use of numerous FreeBSD components in Mac OS X.

There are only two precepts that must be adhered to when using BSD licensed code:

• You are free to redistribute the software, in binary or source form, as long as the copyright, conditions and disclaimer are present (wording here).
• Don't claim you wrote the code.

So, in summary, with exception for the obligation to mention the origin of the code and the disclaimer, a developer is free to do with BSD licensed code whatever he wants. Whether as a corporation or as an individual, free or proprietary, source or binary.