From: Simon Coulter
An alternative is to write CGI applications either directly or via a
framework such as CGIDEV2 but even that seems more work than
typical RPG developers are prepared to embrace.
CGIDEV2 has been fairly successful, but it takes something of a crowbar to pry the 5250 interface from the hands of RPG developers. To be fair, it seems that a lot of RPG developers are supporting and maintaining green-screen systems that sprung up & flourished in the 80s and 90s, which for any number of reasons have withstood enormous pressure to replace with "modern" alternatives - most of which are geared to migrate applications off the platform. It's driving migration vendors crazy - why won't those stubborn RPG developers relent!
The cycle continues. We're discovering a number of competitors in the K-12 software market that went head-long into Java Swing development 10-12 years ago, which are becoming ripe for replacement by a native IBM i alternative, using standard browser interfaces.
If there is a danger in adopting Flex, it would be that you fall into the same trap that Java Swing developers did, which was to transfer too much application logic to the client.