1. An electronic commerce system, comprising: a global content directory server coupled with one or more seller databases over a network, the global content directory server providing a plurality of buyer computers access to the one or more seller databases, the global content directory server comprising: a storage medium stored therein a schema translation tool comprising: a storage medium stored therein a mapping module configured to: receive source schema data and target schema data, the source schema data and the target schema data each comprising a taxonomy comprising a hierarchy of classes into which products are categorized, wherein the target schema data comprises a different taxonomy then the taxonomy of the source schema data, at least the source schema data further comprising a product ontology associated with one or more of the classes, each product ontology comprising one or more product attributes, at least the source schema data further comprising one or more pointers identifying one or more seller databases and associated with at least one source class, the one or more seller databases including product data associated with one or more products categorized in the source class; generate a graphical representation of the taxonomies of the source schema data and the target schema data, the graphical representation allowing at least one of the plurality of buyer computers to graphically associate classes of the source schema data with classes of the target schema data; communicate the graphical representation to at least one of the plurality of buyer computers; and associate one or more source classes of the source schema data with one or more target classes of the target schema data; and a storage medium stored therein an ontology generation module configured to generate a product ontology for each of the target classes, wherein at least one of the target classes is a parent class and the product ontology for each target class is based on the product ontologies of the associated source classes by determining an intersection of the product attributes included in the product ontologies of the target classes.