AVIX for PIC32MX and AVIX for PIC24-dsPIC use the MPLAB development environment. The MPLAB screen dump to the right shows a sample of an application running in the MPLAB simulator consisting of four threads.
RR_Thread1, 2 and 3 are threads running at the same priority and thus scheduled in a round robin fashion. Thread HP_Thread has a higher priority and wakes up periodically preempting whatever thread is running at that moment since it has the highest priority.
With the AVIX tracing you can exactly see what is going on and whether or not the threads behave as intended.