For the last fifteen years, some commentators have predicted <A HREF="http://searchdatacenter.techtarget.com/originalContent/0,289142,sid80_gci1189800,00.html?track=sy185">the demise of the mainframe</A>, as customers move away from mainframes to Wintel or Linux/Unix platforms; and for fifteen years, for very good reasons, mainframe users have failed to do so. Nevertheless, over the same fifteen years, non-mainframe platforms have steadily eroded the mainframe's advantages in performance, scalability, and robustness, while maintaining their strengths in open flexibility that leads to easier incorporation of new technology, and claiming advantages in TCO. Do these facts make migration a better idea today? Or does the question not arise, because migration is too difficult to perform?