As with almost any software development project these days, particularly when development resources are limited, it’s hard to keep up with technology. As described in the History and Purpose section, the data behind the catalog has been developed over several years and as such is currently at various levels of compatibility with current best practices for linked data.

Because the data in the catalog is essential to facilitating the current development efforts of the Perseus Digital Library and the new Open Philology Project, and we also believe it can be a valuable tool for others in the Digital Classics and Digital Humanities communities, we made a decision to release the data and the catalog interface to it before we could claim full compliance with Linked Data standards. Instead we are taking an incremental approach to compliance.  This coincides with a larger effort of the Perseus Project to make all of its data available as proper Linked Data.

We have started by thinking carefully about the URIs that we are using to name and address the Perseus texts,  catalog metadata, and other data objects from the Perseus Digital Library, ensuring that these URIs will be stable and properly dereferenceable. Publishing and supporting these URIs was a core requirement for 1.0 Release of the catalog.

The URI syntax for the objects in the Perseus Catalog is described on the Catalog Data URIs page.  The URI syntax for texts, citations and other data objects in the Perseus Digital Library is described on the Perseus Updates Blog.

As of the 1.0 Release, URIs are used to name all Textgroups, Works, Editions and Translations in the catalog, and we have published alternate versions of these URIs for the HTML and Atom resource formats currently available for the catalog data.  We have also linked the texts in the Perseus Digital Library to the Perseus Catalog.  And finally we have linked the canonical data URIs for the Perseus texts and citations to the catalog via HTTP 303 redirects, so that if a text or citation addressed using a Perseus data URI is not yet available in the Perseus Digital Library, users of these URIs can be redirected to any bibliographic information available in the Perseus Catalog for the requested resource.

The next steps on the roadmap to linked data compliance will be:

• to release all the Perseus Catalog data as RDF triples, available via common RDF serialization formats, including RDF/XML and JSON-LD.
• to add RDF-A attributes to the HTML displays of the Perseus Catalog