I so understand this http://www.cs.princeton.edu/courses/archive/spr09/cos333/bea... way better than clojure. What matters? number of lines or readability? and I am sure the Clojure implementation would be better understood by people who understand lisp. Ofcourse I haven't played with clojure or any lisp dialects and the main reason for that is when I see a lisp code I see only "(" and ")". I still don't know how to get out of that.
Skiena is an awesome professor too and teaches in SUNY StonyBrook but the sad part is he never teaches SB's algorithm course. Its an amazing book and recommend everyone interested in algorithms to read it.
Now how is this different from pulse.yahoo.com? I believe Google have been great in cloning yahoo products than facebook with enhanced search functionality.
Few example
Mail (yahoo is still kicking google ass with their new beta mail product.Seems promising)
Maps (google's maps kicks every products ass.Awesomely done product but a clone from yahoo maps.)
Finance ( Yahoo way way ahead)
Search - no comments :) Its google all the way
News - (Yahoo all the way)
Messenger
All these products resemble perfect clone of what yahoo has and google has done the same thing and have failed in those products which they have invented themselves(wave- [though I loved it] etc). I am excluding their acquisitions (youtube,android etc).
So finally its safe to say Google clones Yahoo products than facebook.