This competition among vendors "definitely helps - it never hurts to play one against the other," said Sievers.

It also allows Sievers to take advantage of the relative strengths of vendor release cycles. If he feels one vendor is ahead of another in a particular technology in a given year he may focus on that vendor.

Supporting multiple vendors "has it challenges because you end up with two or three sets of tools," said Sievers.

Jean Bozman, an analyst at IDC, said it isn't a coincidence that these users are pitting multiple vendors against each another. It's a historical trend.

In era of the IBM-compatible mainframe, Hitachi, Amdahl and IBM competed.