Big iron and open source join forces: IBM's improbable embrace of Linux two years ago now...

For decades, IBM mainframes have set the standard for reliability and manageability. Core applications have long enjoyed those big-system benefits, but an increasing number of critical services--including Web, file and print, mail--have not. Now IBM's wholehearted adoption of Linux has introduced a wildcard that is changing the picture dramatically.

Under IBM's venerable wing, Linux--and the universe of software that comes with it--has become a fully supported mainframe operating system. "We are so confident of how reliable Linux is," says Dan Frye, director of IBM's L