When I wanted to contribute patches to make Python's build process on Solaris more like the
build of Python that ships with Solaris, the Solaris engineers were very friendly and helpful. :-)
More so than the Python developers, I'm afraid. :-(
Also I recently had a very pleasurable interaction with the ZFS crypto developers when they asked
for some general advice on crypto design. :-) They didn't end up using most of my proposals,
but I think this was probably for the very good reason that what they have now is "Good Enough"
and they need to hurry up and finalize it and ship it before Oracle takes the reins. In contrast
when I offered suggestions about crypto to the git developers, Linus publicly ridiculed my
Also when I tried to find out why the GPL'ed UltraSPARC T2 processor had its crypto accelerator
omitted from the source code the Sun employees responsible for the T2 were polite and
responsive to my inquiries.
At the moment I can't recall any negative interactions that I've had with any Sun employees on
open source projects, while I find it easy to think of negative interactions I've had with developers
on various other open source projects.