Those are two different things.
A) For the file extension to be removed, your URLs would be transformed from:
www.domain.com/home.html
to
www.domain.com/home
B) If you don't want the name of the actual file containing the currently viewed page to be displayed, you could load your site using traditional HTML frames and ALL of the pages will appear to be loaded from
www.domain.com
You could probably do the same using iframes, like we did in another thread on this forum. There are probably other options available as well that aren't coming to mind for me right now.
So, are you looking for 'A' or 'B' above?
Peace...