Colectica Reader - The Free DDI 3 Viewer: Colectica Reader is a free tool to view DDI 3 metadata. View DDI 3 Metadata: Colectica Reader runs on Windows.Use Colectica Reader to view your DDI 3 metadata from Colectica Designer, Colectica Express, or other DDI applications. Colectica Reader performs multiple levels of validation on your DDI 3 metadata. Ensure your metadata validates against the DDI 3 XML schema and all references are valid. Friendly XML Viewer: Colectica Reader displays your XML with helpful syntax highlighting and hierarchical folding, making it easier to find what you are looking for. Don't have DDI? No problem. Learn how the rest of the Colectica platform enables you to create DDI without any knowledge of XML, or view some DDI samples. Or, contact us about our metadata consulting, metadata preparation, or custom development services.