Fondue - pronounced [fahn-DOO]
The word fondue is derived from the French word "fondre" which means "melt".

History
This warm cheese dish originated in Switzerland and more specifically in the Canton of Neuchatel. The dish consists of at least two varieties of cheeses that are melted with wine and a bit of flour and served communally out of pot called a "caquelon". Long forks are used by each guest to spear a cube of bread then the bread is dipped into the cheese and eaten.

Fondue dates back to the 18th century when both cheese and wine were important industries in Switzerland. The simple to prepare meal utilized ingredients that were found in most average homes.
 
The Swiss Tradition
Each component of a traditional Swiss fondue plays an import role. Most recipes we see for "traditional" Swiss style fondue are a combination of two cheeses, Gruyere and Emmenthaler. These two cheeses are combined because either cheese alone would produce either a mixture that was too sharp or too bland. The cheeses are most commonly melted in a dry white wine which helps to keep the cheese from the direct heat as it melts as well as to add flavor. The Kirsch (a clear cherry brandy) was added if the cheese itself was too young to produce the desired tartness. The garlic was for additional flavoring while the flour or cornstarch assists in keeping the cheese from separating.

Another Swiss Custom - If a lady loses her bread in the fondue, she pays a kiss to the nearest man; if a man loses his bread, he provides the next round of drinks. It is not good form to make someone else lose their bread.

The Traditional Pot (Caquelon)
The traditional fondue pot is called a caquelon [kak-lohn] and is made of a heavy earthenware. Other variations include glazed ceramic or enameled iron. All variations are heavy to help promote even heat distribution and heat retention. The fondue is heated on your cooktop in the caquelon over low to medium heat then transferred to the table and placed over an alcohol burner or a hot plate.

Etiquette
Given Fondue is a "communal" meal there are a few basic guidelines to follow. To eat cheese fondue spear a piece of bread using a fondue fork and dip it into the pot. Twirl the bread cube gently in the cheese to coat it. You'll want to let the bread drip a bit before you put it in your mouth. This will allow the excess to drip back in the pot and also allow time for cooling. When you put the bread in your mouth try not to touch the fork with your lips or tongue because the fork does go back in the pot. Alternately you can use a dining fork to slide the bread off the fondue fork then eat it with the 2nd fork. This is probably more cumbersome than necessary.

To eat meat fondue, spear a piece of meat and plunge it in the hot oil. Allow it to sit until the meat is cooked to your liking. Remove the fork and place it on your plate. Use your dining fork to slide the meat off the fondue fork. Then use your regular fork to dip the meat in the sauce as desired. Then eat using your regular dining fork.

The Bread
A baguette works very well although any crusty French or Italian style breads will do. When you slice the bread make sure that each piece includes a bit of the crust. This crust helps keep the bread on the fork after it is placed in the cheese.

Fondue Styles
There are as many styles of Fondue as they're are peaks in the Alps! In fact each canton in Switzerland has their own "traditional" style fondue.

Fribourg - The fondue from this region combines Gruyere with Vacherin a Fondue. The wine and Kirsch is only added if the cheese is not fully ripened. When the wine is not used, guests dip their bread in plum schnapps, then into the fondue.

Geneva - It is common to use three cheeses, Gruyere, Emmental and Walliser Bergkase. A regional addition may include chopped morel mushrooms.

Glarus - First a roux is made of butter, flour and Gruyere and Schabzieger cheeses are added.

Eastern Switzerland - Appenzeller and Vacherin a Fondue are the cheeses of choice combined with a dry cider.

Vaud - The locals roast and chop garlic then combine with Gruyere cheese.

Neuchatel - A combination of two thirds Gruyere and one third Emmental, or a half and half version with Neuchatel wine.

Other Fondue Styles

Oil Fondues - tender cuts of beef, poultry and seafood, as well as veggies are quickly fried in hot oil, then dipped in a variety of sauces.

Broth Fondues - tender cuts of beef, poultry and seafood, as well as veggies are cooked in simmering stock then dipped in a variety of sauces. Noodles and leafy veggies can be added at the end to create a tasty soup.

Dessert Fondues - chocolate is usually the star here - heated with cream and often liqeuer the used as a dip for fruits, cake or cookies.

Cooking and Serving Tips
Keep the fondue warm over as low heat as possible to avoid scorching the cheese, or overheating the oil.

Make sure your recipe includes a bit of corn starch, all purpose or potato flour. The starch in the flour helps to keep the cheese in suspension which keeps the fondue from separating.  Adding a small amount of lemon juice to the wine increases acidity which in turn helps to break up the cheese.

When you add the cheese to the simmering wine, stir in a zig zag rather than circular motion to help break up the cheese.

Preparation and Serving Tools
Little is needed in the way of special tools for preparing and serving fondue.

Pot Basics
Most fondue sets come with a tray, a container for an alcohol or a "canned heat" product such as Sterno, a stand, and a pot. The canned heat container ideally should be fitted with a "diffuser" to adjust temperatures as needed.

Source Credits: GourmetSleuth.com, Epicurious.com, Culinaria, European Specialties, 1995, 2000, Konemann, Gourmet International Fondue, Arthur Barrett, Doubleday Egg and Cheese Cookery, TimeLife 1980