XML is now becoming an industry standard for data description and exchange. Despite this there are still some questions about how or if this technology can be useful in High Energy Physics software development and data analysis. This paper aims to answer these questions by demonstrating how XML is used in the IceCube software development system, data handling and analysis. It does this by first surveying the concepts and tools that make up the XML technology. It then goes on to discuss concrete examples of how these concepts and tools are used to speed up software development in IceCube and what are the benefits of using XML in IceCube’s data handling and analysis chain. The overall aim of this paper it to show that XML does have many benef...