One of the problems software engineers face when internationalizing a product is discovering too late that the product design cannot accommodate international requirements. This presentation is to help designers, architects, implementers, testers, and writers understand the areas where internationalization can affect appearance and structure. User interface design and localizability are discussed, some performance issues are covered, and tips for implementation are provided. Common misconceptions about internationalization are debunked, and a few other sources of information are referenced.