AS/400 is still quite popular in SA, although I wonder what the stats are like for new business. All the banks run 400's in the background somewhere and almost all the insurance companies run 400's as their primary systems. A technician from TCM once told me there are over 1000 companies running iSeries in JHB. You'd be hard done to try and match them for their number crunching/transactional power. Also what other technology do you know that has "dominated" it's market consistently for 30 years?
And they are semi-evolving, /free syntax, Web Shere for Java (i think), and there is even a RPG.NET available. There's only so much you can do with 5250.
(As an aside note their are rumors of IBM buying Sun for around $6billion so I think they know how their business works.)
Maybe someone else has different experience but my biggest problem with RPG/iSeries is this: The systems are old, massive, but they work, so you get a lot of "if it's not broke don't fix it". Which means you spend 85% of your time doing code maintenance/debugging then actually writing anything new. With a bit of add this functionality here and this bit there for good measure.
