Looking for feed aggregator

I saw a rss feed reader and i really liked it. But i could not get its code to see how its made. I have added the link below:

I am looking to create a similiar feed aggregator(using RSS & Atom). I like to rip things and learn how its made. So, i am looking for a feed aggregator that is similiar to the one i linked above. Can anyone pls help me???

I dont mind which every language its coded in. I just prefer one that does not depend on a database.