Bringing modern IDE features to Semantic Web formats with the Semantic Web Language Server

Abstract

Authoring Semantic Web documents such as ontologies or SPARQL queries is error-prone, often leading to interoperability issues, validation failures, or incorrect reasoning. To address these challenges, we present the Semantic Web Language Server (SWLS), a tool for Semantic Web practitioners that integrates IDE-like functionalities such as real-time syntax validation, intelligent autocompletion, and SHACL-based diagnostics into modern code editors. SWLS follows the Language Server Protocol, allowing seamless integration with popular code editors such as Visual Studio Code and NeoVim, while currently supporting multiple Semantic Web formats including Turtle, JSON-LD and SPARQL. This demo accompanies an accepted ESWC 2025 resource paper and showcases SWLS in an interactive web-based environment, where users can explore its features across four dedicated editor panels: (i) an RDF instance

data editor, (ii) an ontology editor, (iii) a SHACL shape editor and (iv) a SPARQL query editor. The demo highlights SWLS's ability to detect syntax and semantic errors, suggest completions based on dereferenced ontologies, and assist users in writing coherent SPARQL queries. By improving the development workflow and addressing common pitfalls, SWLS aims to enhance the usability of Semantic Web technologies and facilitate broader adoption.