At last year's IBM Innovate Conference (formerly the Rational Software Developer's Conference), we presented this deck about using Java on the z/OS mainframe. Since that time there have been a couple of major releases of the IBM Rational Developer for Enterprise product and at this year's conference there will be extensive coverage of version 9.1 of the Rational IDE's. These new versions were just announced and went live for general availability this week.
If you will be developing on Java on z/OS and need to access MVS datasets, be sure to read through the presentation below, and it is a good primer on the platform.
If you develop Java on the mainframe, check out our link collections on Delicious:
https://delicious.com/strongback/jzos
https://delicious.com/strongback/rdz
https://delicious.com/strongback/javaLabels: java, mainframe, zos IBMInnovate