Hi Madhu,
I wrote a simple ETALIS counting sliding window in etalis/examples/count_sliding_window
It is quite simple - computes the sum of the last 5 events. I didn't make it exactly like in EP-SPARQL, but somehow simpler (using Prolog predicates and the dynamic database). I hope this is ok with you. The EP-SPARQL examples are working correctly, but EP-SPARQL is still experimental and now I have no time to look into it. The example that I wrote is less efficient, but I guess if sliding windows is all that you need for the moment, you have them this way.
Paul.