Diet Coke
Diet Coke does not use a modified form of the Coca-Cola recipe, but instead an entirely different formula. The controversial New Coke, introduced in 1985, used a version of the Diet Coke recipe that contained high fructose corn syrup and had a slightly different balance of ingredients. In 2004, Coca-Cola introduced Coca-Cola C2, which it claims tastes much closer to Coca-Cola but contains half the carbohydrates. In 2005, the company introduced Coca-Cola Zero (replaced by "Coca-Cola Zero Sugar" in 2017), a sugar-free variation of regular Coca-Cola.
Storm (soft drink)
Storm was a lightly carbonated, caffeinated lemon-lime flavored soft drink. It was test marketed by PepsiCo in some areas of the U.S. in 1998 as part of Pepsi's attempt to become more competitive in the U.S. clear lemon-lime soda market, one which was dominated by Coca-Cola's Sprite. Storm differed from Sprite in that its flavor was uniquely subtle and had a very slight bitterness to it, as well as having caffeine.