LinkResolvers

Linkresolvers are software components that interpret, resolve, and normalize productively ambiguous reference links. In the context of the scholarly web they focus on converting identifiers such as DOIs, handles, ORCIDs, or publisher‐specific URLs into canonical URLs that point to the definitive resource. A linkresolver interrogates a metadata service, verifies the existence of the target, resolves HTTP redirects, and often assembles a metadata record that can be served to a user or client application.

The need for linkresolvers arose with the growth of digital publishing, where articles were frequently cited by shortened URLs or by identifiers that point to a journal’s staging environment. Early tools were simple HTTP proxy services, but modern linkresolvers typically use a blend of web‑recrawl, citation‑policy parsing, and client‑side rewriting. They must handle chained redirects that may traverse multiple authority domains, remove query strings that alter content, and detect broken or expired links. Academic libraries deploy linkresolvers to grant institutional users direct access to subscriptions, and libraries’ discovery systems rely on linkresolvers to present users with a “Link Workspace” that aggregates all available access routes.

Typical features include: 1) a lookup service that takes an identifier and returns the final URL; 2) a linkscape mapping that identifies all available hosts and delivery methods; 3) an analytics interface that tracks click‑through rates and broken‑link occurrences; and 4) integration hooks for discovery platforms and SPARQL endpoints. Open sources such as the Open Semantic Link Resolver (OSLR) demonstrate the capacity to endow a simple text string with discoverability, often exposing RDF triples that describe the content. Commercial offerings such as Crossref’s link‑resolver service embed links into scholarly publishers’ platforms, while institutional bitstreams such as EPrints and DSpace integrate custom resolvers to route DOIs to hosted content. The present design of linkresolvers reflects an attempt to standardise the interface between metadata stores and end‑user requesters, ensuring that every scholarly link points to a precise, stable, and optimised resource.