M&M's is a brand of colorful button-shaped candies produced by Mars, Incorporated. The candy shell, each of which has the letter "m" printed in lowercase on one side, surrounds a filling which varies depending on the variety of M&M's. The original candy had a milk chocolate filling which, upon introducing other varieties, was branded as the "plain" variety. "Peanut" M&M's, which feature a peanut coated in milk chocolate and, finally, a candy shell, were the first variety introduced and remain a regular variety. Numerous other varieties have been introduced, some of which are regular widespread varieties (such as "peanut butter", "Pretzel", "Almond", "caramel", and "dark chocolate"), while others are limited in duration or geographic availability.
M&M's originated in the United States in 1941, and are now sold in as many as 100 countries. They are produced in different colors, some of which have changed over the years. The candy-coated chocolate concept was inspired by a method used to allow soldiers to carry chocolate without having it melt. The company's longest-lasting slogan reflects this: "Melts in your mouth, not in your hand."
- M&M's candy fades to black and white, a December 30, 2003 Reuters article via USA Today