Software Geopolitics: How Much Linux Kernel Code is GPL 2 Only? At Most 60%

“Linus and other Linux kernel developers have made it very clear
that the kernel will continue to use the GNU GPL version 2, and not
move to the GPL 3. But the fact that the kernel is ‘effectively’
GPL 2 does not mean that all of its code is GPL 2 only–by this I
mean that some of the code may be dual-licensed. To get a working
Linux system, you must of course use the GPL 2 license. But with
dual-licensed code you can use another license when you use it
somewhere else, say if you want to use the code in another kernel
(perhaps OpenSolaris). But how much of the Linux kernel code is
dual-licensed? That is what I tried to find out.

“I am not a lawyer. But I do meddle with code. So, to
investigate this, I wrote a short program to scan the Linux kernel
code (version 2.6.20) and check what licenses appear in it…”

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