42linked

42linked is a web-based platform designed to create and navigate a networked graph of digital resources. It treats links between pages, datasets, documents, and other resources as first-class entities, allowing users to attach metadata, annotations, and provenance to each node. The project emphasizes interoperability with open standards and aims to simplify discovery across disparate services by exposing a connected data layer.

Core features include a graph data model, a browser extension for saving resources, a collaborative tagging and annotation system, and an API for programmatic access. Nodes can represent resources, people, or concepts, with relationships such as cites, derives from, or related to. Privacy controls enable users to decide who can view or edit each connection, while moderation and reputation systems support quality control in community-curated graphs.

Technology and standards: 42linked stores data in a graph database and exposes a RESTful API, with optional support for GraphQL and RDF-based Linked Data. It supports persistent identifiers and standard ontologies to enable cross-service linking and data portability. The platform is designed to be deployable as a hosted service or as an open-source stack for on-premises use.

History and reception: The project originated from a collaboration among researchers and developers aiming to unify linking practices on the web. It released a public beta in 2020 and has since evolved through multiple releases, focusing on interoperability and performance. Critics have noted the potential benefits of a connected knowledge graph for research and education, while raising concerns about privacy, data quality, and complexity of use.

See also: Linked data, Semantic Web, Knowledge graph, Web annotation.