Bill Studenmund <wrstuden@nas.nasa.gov> writes:

> The entire kernel doesn't become GPL'd, but the inclusion of that one file
> restricts your ability to distribute that kernel - you have to distribute
> it under terms as free as the GPL (though not necessarily GPL'd).  Chunks
> of code currently in our kernel source has other restrictions, such as
> advertizing clauses. These clauses are more restrictive than the freeness
> of GPL. Thus they can't mix..

No, it's not that simple.  It requires you to distribute the entire
`derivative work' under terms with the same virus clause -- meaning
that any derivative of that work is then `infected' by the GPL -- EVEN
IF THE ORIGINAL GPLED CODE IS REMOVED.

This is why it's known as the `General Public Virus', and why it's not
welcome in NetBSD.