The first crack came with the advent of Unix. These servers began to offer many of the Java functions of the mainframe. But they aren't the same. Mass. IBM's move was spurred by the rapid growth of e-business. It's on a mainframe.
Internet technologies are behind the rejuvenation of the mainframe.
As companies became more global in orientation, they needed to centralize their computing operations. Because they are always open, their computing environments are less predictable. IBM wants to devise common open computing platforms on which it could sell its hardware, software applications, middleware and an array of technology services. The dynamic partitioning capacity of the z900 builds on the mainframe's known high reliability. It allows tens of thousands of virtual Linux servers to be created, maximizing productivity by enabling IT managers to allocate system resources that aren't being used.