In this chapter, we study what semantic technologies can bring to the e-business domain and how they can be applied to it. After an overview of the goals to be achieved by e-business applications we detail a large panel of existing e-business standards, with a specific focus on B2B (Business to Business) and their current modus operandi. Furthermore we also present some of the most relevant e-business ontologies. We then argue that the use of semantic technologies will simplify the automatic management of many e-business partnerships. However the construction of ontologies brings a new level of complexity that might be facilitated by automating the great part of the generation process. For this we have developed the Janus system, which is a prototype to help with the automatic derivation of ontologies from XML Schemas, the de-facto format adopted in e-business standard applications. Differently from existing systems it permits to retrieve automatically conceptual knowledge from large XML corpus sources and is based on the use of the Semantic Data Model for Ontology (SDMO) whose advantages are presented in this chapter.