IBM's mainframe bubble bursts and growth stalls

Red Hat still glowing, but Big Blue's been bruised by investors
In its last few quarterly results announcements, IBM has trumpeted unexpectedly strong growth in its mainframe business, and that's helped the technology titan to just-about deliver promised mid-single-digit revenue growth in constant currency. But in its Q3 results announcement on Wednesday, Big Blue revealed mainframe revenue fell 19 percent – and that overall growth came in at just one percent or two percent in constant currency.…