If you need access any asset you will have understand the following concepts:
Register: All meta-data about your assets in your solution will be localized in this tier. You can get information about these meta-data using JAXR or UDDI clients. See at documentation more details how to develop these components.
Repository: All real archives of your assets (e.g., WSDL for Web Services, XSD for Schemas and others) you can access then trough WebDAV clients. See at documentation more details how to integrate CentraSite with WebDAV clients.