g1smd - 1:07 pm on Dec 2, 2011 (gmt 0)

No need to ever expose the server technology in the URL.

Also, say your site moves from static .html files to a dynamic .asp site then moves again to an open source .php package. With extensions you've a mess of redirects to install on the first move and then to update and add to with the second move.

With extensionless your URLs are the same for all three versions of the site.