This would be a fairly “narrow” market opportunity but with IBM Rational dropping support for RAD and WSAD it is also dropping WDSc (Websphere Development Studio Client) for System i. WDSc is development tool for developing ILE RPG and Cobol programs targeting the System i running i5/OS. At the simplest what would be needed would be source editors for the ILE RPG and a simple call to submit that source to the compiler on the System i. Also it would be helpful to have a compiler error reporting component.
There is a fairly large community of users affected by the change IBM is making. I think it would be worthwhile for you folks to explore the possible opportunities here. Feel free to contact me if you need more information.