A mainframe (also known as "big iron") is a high-performance computer used for large-scale computing purposes that require greater availability and security than a smaller-scale machine can offer. Historically, mainframes have been associated with centralized rather than distributed computing. IBM emphasizes that their mainframes can be used to serve distributed users and smaller servers in a computing network.

The mainframe is sometimes referred to as a "dinosaur" not only because of its size but because of reports, going back many years that it's becoming extinct. I.B.M. overhauled the insides of the mainframe, using low-cost microprocessors as the computing engine. The company invested and updated the mainframe software, so that banks, corporations and government agencies could still rely on the mainframe as the rock-solid reliable and secure computer for vital transactions and data, while allowing it to take on new chores like running Web-based programs.

Also driving interest in the market, IBM has made the mainframe more useful. Ten years ago, IBM added Linux support to its System z mainframes. This gives System z users great flexibility and allows them to consolidate a variety of workloads. A typical use of Linux on a System z is to run, for example, a transaction processing application on the zSeries/Operating System (z/OS) and Web services applications on Linux side-by-side on the same machine.

Unfortunately, many IT professionals lack mainframe programming and administration skills. But is it worth learning theses skills now? Definitely, yes. A large percentage of the people who work on mainframes are approaching retirement age. One number frequently cited since about 2005 is that about 80 percent of the people who support mainframe operations are 50 years old or older. That puts this group at about 55 years old now. So in the next five to 10 years, many organizations anticipate large-scale retirements from this part of their staff.

Maples ESM Technologies MFAP - Main Frame Application Program and MFSA – Main Frame Systems Administration programs are equally good and the opportunities also are similar. It all depends on individual’s preference to choose between Software Application Development and Systems Administration / Maintenance