I need a way of parsing web page, and getting a list of all its component, and this is my first problem.

See WWW::Mechanize::Firefox

Or Parsing HTML / Re^4: Parsing HTML, A regex question , NASA's Astronomy Picture of the Day / Re: NASA's Astronomy Picture of the Day

How can I emulate 4 concurrent downloading threads?

You probably don't want to do that

In reply to Re: Timing web page download. by Anonymous Monk
in thread Timing web page download. by Eyck

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