The Job Scheduler is a 32bit engine but you can run it on each supported 64bit platform.
The Job Scheduler requires a Sun Java Runtime Environment (JRE) 32-Bit at least version 1.6.x.
For AIX you can use the IBM Java 32-Bit at least version 1.6.x, too.
You can install the 32Bit Java in parallel to a 64Bit version.
See "Z-JAVA-101 Java Virtual Machine is not started" for more information.
On 64Bit Ubuntu it is possible that you get "/bin/sh: ./bin/scheduler: not found", for this see here.