Pedro is a tool that combines rapid data modelling and ontology services. It renders data entry forms from an XML schema, allowing users to create data files that conform to the data model. Users can mark up text fields with controlled vocabulary terms supplied by ontology services. Originally developed for a proteomics consortium, Pedro has since been used in other domains like genomics and security. It validates data files against the underlying data model and remembers where controlled vocabulary terms came from through its ontology services.