Can I port 4.4BSD-Lite's TCP/IP protocol stack soure code to my own OS kernel which is GPL Licenced?

[Chuck Swiger]

On May 4, 2008, at 6:32 AM, hlwhyw at shtel.net.cn wrote:
> Can I port 4.4BSD-Lite's TCP/IP protocol stack soure code to my own  
> OS kernel which is GPL Licence?

Modern 2- or 3-clause BSD licenses are fully compatible with the GPL,  
as are most "simple, permissive" licenses like the MIT/X11, Zlib, and  
similar licenses.  The old 4-clause license with the "advertising  
clause" is not GPL-compatible.

> I know that 4.4BSD-Lite is BSD Licenced.  Is it legal to port BSD  
> Licenced code and change it to GPL licence?

You are not allowed to remove the copyright statement or the original  
BSD license, but you can take BSD-licensed code and combine it with  
other software to create a derivative work which you then distribute  
under the GPL or even a proprietary license, if you wish.

Eric Raymond and his wife, Catherine (who is a lawyer), have written  
some documentation about this specific issue here:

   http://catb.org/~esr/Licensing-HOWTO.html#id2787981
   http://catb.org/~esr/Licensing-HOWTO.html#changing

There was also a thread here:

   http://www.crynwr.com/cgi-bin/ezmlm-cgi?3:sss:15819:200804:ohmgonchmnecmnandlnk#b

Regards,
-- 
-Chuck