use of the kernel and licensing

[Joe]

kpneal at pobox.com wrote:
> On Sat, Mar 30, 2013 at 09:22:22AM -0400, Maikoda Sutter wrote:
>> If I use the kernel as a basis for my own system and modify the kernel
>> should I still maintain the licensing of the kernel bits, or could release
>> it under it's own license?
>>
>> For example: I would like to rewrite the headers to be 100% POSIX compliant
>> and I do like the BSD license, however I was planning on releasing my whole
>> system under the Unlicense, I understand that certain headers and code that
>> I do not modify has to be released under the BSD license as that is the
>> original license of the code, however for headers or code that I modify can
>> I release it under the Unlicense (http://unlicense.org/)?
>>
>> I do plan on giving credit where it is due and such to the wonderful
>> developers of FreeBSD and those that wrote the original code because
>> without you I would not be able to produce so rapidly that which I am
>> looking to produce I just would like clarification on the extent that I
>> would have to license things via the BSD license.
> 
> You cannot yourself change the license on code you do not hold the copyright
> on. Period.
> 
> If you make changes and redistribute them then add your copyright notice
> with license to the files. Do not remove the existing copyright notice(s)
> and license(s).
> 
> You hold the copyright for stuff you wrote, but the original copyright
> stays for the parts that did not come from you. "Parts" means any fraction
> of a file from the whole file down to small amounts. You are allowed to
> add restrictions (unless the existing license says you can't), but you are
> not allowed to loosen the existing restrictions (unless the existing license
> says you can). Also, it follows from the copyright that your license only
> applies to the parts copyrighted by you.  The existing licenses are similar
> in that they apply only to their parts of the file. All licenses must be
> followed when the file is treated (copied, used, etc) as a whole.
> 
> Make sure your license isn't incompatible with the license that applies
> to other parts of the same file. If that happens then how it will turn out
> in court is anyone's guess. The file may not be usable by the public, or
> the incompatible license terms added by you may be struck down, or a judge
> could cook up something else. It can't be predicted in advance so just
> don't even go there.
> 
> "Giving credit where it is due" is an important social convention, and I'm
> glad to see that you aren't planning on doing anything unethical like
> breaking it. But copyright comes from the law and thus must be obeyed even
> if you wanted to break purely social conventions.
> 
> Read up on copyright, and when you do pay close attention to the reliability
> of the source. The issue has become very political in the past 15 years
> or so. Don't be badly advised by someone who has their own agenda. Most
> people, to varying degrees, have their own agenda.
> 
> Finally, if money is at stake (directly or indirectly) I strongly advise
> talking to a copyright lawyer in particular. That's just general advice.
> Taking advice from random people online is not a good idea if any money
> is involved, but I'd give the same advice to my best friend. The general
> rule applies here as it does elsewhere: "You get what you pay for."
> 

Does one have to file legal paper work with the government to be issued 
a copyright on software?

Does any software not having a copyright statement or any license 
comments included in the source mean that it's public domain?