Emmenthal (Emmentaler) is the famous "Swiss Cheese" with the big holes and in fact in the U.S. it is most frequently referred to generically as Swiss Cheese. Although this is often a cheese from Switzerland it is also made in France (actually considered the best), Austria and Germany, each with its own characteristics. The cheese is naturally lower in salt, and fat too because it is made with partially skimmed cow's milk. This is one of many cheese with an inedible rind.
The flavor of a good Emmenthal is sweet, nutty and at the same time fruity. Aside from being a primary ingredient in Swiss Cheese Fondue it is a wonderful melting cheese and works well in casseroles, used in soups or simply melted on or server in sandwiches. Of course it is a natural on your cheeseboard too with crusty bread, and thin slices of ham. Serve with a light fruity wine such as a Beaujolais.
Many "garden variety" versions of Emmethal are ubiquitous. For a superior cheese make sure it the rind bears the word "Switzerland" imprinted on it. Most grocery stores carry at least one brand. A good cheese shops should have some stellar examples. You can even shop online at Amazon.com Frantal Emmental for some excellent French and Swiss brands.
If you don't have Emmenthal you can substitute equal amounts of: