This is a little bit unfair for the blue guys :) ISPF is far more than a set of screens to invoke TSO commands. The panels (that's how ISPF screens are called) are just a part of the whole thing. ISPF integrates with TSO, so we are talking about: - The TSO command language (CLIST language) and also the REXX language. - The panel facility. - The skeleton facility. It is quite easy to "simulate" the ISPF panels (you just need DCL to do it, I did it when I worked with DEC machines in a mostly IBM-centric company), but that would be just the user interface. The APIs provided with ISPF are way beyond that... I was planning on developing a simple format for defining the panels, mapping the options to DCL and any params / switches they need. I am aware that ISPF can be used for way more than the basic IDE / sysop functions that it comes with by default, don't some ISVs actually build their software using ISPF panels as the interface? I just thought a IBM mainframe lookalike interface to VMS would be amusing if nothing else. Sampsa