Environmentally acceptable products are continuing to gain importance on the market. This review covers programs that are targeted to mark products or services that are less environmentally harmful than others that serve the same purpose, Several environmental-labeling programs were created in the late 1980s and early 1990s. To illustrate the principles of such labeling systems, various programs are presented in detail. The programs were chosen to represent a wide spectrum of characteristics: stringent and less demanding, well-established and recently created, national and multinational, and from various of the world. Similarities and differences, as well as advantages and disadvantages, are discussed.