GPL vs CDDL, Again
I was reading a great article on a DTrace knockoffs by Adam Leventhal. Ok, only one is mentioned in the article - Systemtap - but it’s a very entertaining read and makes me think there’s a fair bit of that green stuff and NIH syndrome, about in the Linux world.
Whilst DTrace is a brilliant bit of technology that is slowly being implemented in various other operating systems, it’s the heated debate in the comments that I want to comment on.
Believe it or not, there is not a single comment from the Linux community that says “Fair cop, Systemtap is a very bad attempt at DTrace. We really should be looking at ways of porting DTrace to Linux“. Nope, instead there a debate about GPLv2 vs CDDL, caused by an attempt to defend why DTrace hasn’t been ported to Linux. The underlying theme from the Linux side is that it’s the CDDL license that is stopping DTrace from being ported to Linux.
I’m not a lawyer, and nor have I studied the GPLv2 or CDDL licenses in depth, but think about it for a moment. CDDL licensed code has been incorporated into other proprietary and open source operating systems, each with their own licenses. If CDDL were the one doing the restricting, surely it couldn’t be included in these products?
My take is it’s actually the GPLv2 that is stopping the porting of DTrace to Linux. It’s the GPLv2 that demands that any code linked with GPLv2 code must not be any more restrictive than the GPLv2. It’s the GPLv2 code that is incompatible with other more restrictive licenses. NOT CDDL - it’s the tolerant one of the two.
I am a fan of BOTH Linux and Solaris, for each of their own merits. What I’m not a fan of is FUD.
I honestly thought that I would forestall the licensing debate by alluding to it in my blog post: so much for that. In my mind, the debate over licensing should come _after_ the code has been written — otherwise it just rings of laziness…
> Believe it or not, there is not a single comment from the Linux community
> that says “Fair cop, Systemtap is a very bad attempt at DTrace.”
I’m biased in the matter, but is it really impossible to believe that systemtap
is more than just “a very bad attempt”?
> My take is it’s actually the GPLv2 that is stopping the porting of DTrace to Linux.
There is no point placing such a blame. The GPL is what it is. The CDDL was
written (partly) to be incompatible with the GPL. Both embody ideologies -
just different ones.
Adam: Unfortunately, as long as there are “incompatible” licenses in ANYTHING, it’ll always be used in debates, especially in the open source community. Who knows, maybe the GPLv3 may help in cutting down these debates and get developers back doing what they’re good at - creating brilliant technologies.
Frank: Fair cop - I did do a bit of finger pointing there - my bad. You’re right, each is what they are, and each license has been devised for their own purposes. Lets hope people can work things out and get the technology they need and want without all the finger pointing.
If proprietary drivers can be used in Linux, then so can CDDL licensed code: it’s just going to take someone a bit of time and effort to bridge the license gap with a bit of code that satisfies both licenses.