Dont get confused with JMeter extentions. I am talking about Java Management Extentions (JMX) counters.
We know how to monitor performance counters which are exposed through perfmon or snmp ..etc.
Like the same way there are many java applications which explose performance counters through JMX. For eg: JVM counters can be accessed from any running java applications through JMX. I want to monitor such counters using Performance Explorer. There are some tools like JConsole does monitor any JMX based counters. But the features are not rich as Performance Explorer. So I want to user Perf Explorer for such counters.