Sun Solaris or IBM AIX?

[abctips]

Hi,

I'd like to get Unix Certified, but I'm not sure
if taking the AIX Sys Admin certification is enough
to not have to be Solaris certified?

Also, when we talk about the 3 types of shells (korn, C,
& bourne) or when we talk about C/C++ scripting in a Unix environment, which Unix are we referring to?
Is it Sun or IBM? Or no difference?

Then there's Linux. Which fits with Linux?

Hmm, I must be either asking stupid questions or
just thinking too hard.

Thanks,
abctips.