> SAP have had an OS X GUI for a few years
As well as various other UNIX-like operating systems ... however, they are inferior to Windows SAPGui in a number of areas, process chains springs to mind ... mainly because SAP built some "very good" process chain editor tool that requires the highly acclaimed ActiveX technology into SAPGui, which is only available on Windows.
So yes, most things can be done on Linux, Mac, Solaris Java-based SAPGui ... however, some things cannot.