Legacy applications contain the time-tested business knowledge, distilled over a long period of time. How best to evolve or reuse these legacy IT Assets, under changing business, economic and IT environments, is a challenge that every mainframe enterprise has to address. Many have tried solving the aging legacy applications by rewriting it in new technology, most have failed to eliminate the legacy. Not because of the technical feasibility of such rewrite, but due to the time, effort and risk associated with these approaches.

IBM Personal Communications provides a rich set of Application Programming Interfaces (APIs) for Windows users to play with host green screens (Terminal emulator screens).