Among Unix, the major competition was, and still is, around Solaris, AIX and HP-UX.

"I think the number three is significant," said Bozman. "The dynamic of three [vendors] is very important."

Users who mix and match three separate hardware vendors are also leveraging the fact that there is lot of standards built into these environments, said Bozman.

But there are also many users who believe that working with one vendor has much merit.

Marco Baptista, the CIO of Inter, a Venezuela-based telecommunications company, uses HP in is IT shop.