SWEO Community Project: Linking Open Data on the Semantic Web

Linked Data Browsers, Mashups and other Client Applications

This page collects software components that can be used implement applications on top of the Semantic Web. The page is not intended to list RDF toolkits that focus on local RDF processing, but toolkits that perceive the Semantic Web as a single integrated information space and help applications navigate this information space.

Listings of RDF toolkits with a more local perspective are found at SemanticWebTools and Developers Guide to Semantic Web Toolkits

The page is part of the LinkingOpenData community project

Linked Data Browsers

Tabulator. See also their papers Tabulator: Exploring and Analyzing linked data on the Semantic Web and Tabulator Redux: Browsing and Writing Linked Data
Disco server-side Linked Data browser.
OpenLink Data Explorer a Web browser extension, and a server-side component of the OpenLink Ajax Toolkit.
Zitgist RDF Browser
DBpedia Mobile Linked Data browser for mobile devices using DBpedia locations as starting points for exploring the geospacial Semantic Web.
Marbles tabular Linked Data browser supporting Fresnel.
iLOD, a simple linked data browser for the iPhone, made by Alexandre Passant.
Fenfire Linked Data browser displaying information as a navigatable graph.
Objectviewer by Troy Self (Semantic Web Central).
zLinks Technology for embedding Linked Data backed popups into textual web content.
Sigma, Live views on the Web of Data
Quick & Dirty RDF Browser Simple RDF browser. Useful for checking RDF or RDFa says what you intended.
Graphity Client Generic Linked Data browser and platform for building declarative SPARQL triplestore-backed Web applications. Apache license.

Linked Data Mashups

Revyu by Tom Heath. Uses Linked Data from DBpedia to augment reviews, for instance with information about a director for a film.
DBpedia Mobile by Christian Becker and Chris Bizer. Combines Linked Data from DBpedia, the flickr wrapper, and Revyu.
Music Mashup by Yves Raimond. Combines Linked Data from various music related data sources. See also.

Linked Data Client Libraries

This section lists toolkits that provide access to the Semantic Web by dereferencing resource URIs.

Semantic Web Client Library The Semantic Web Client Library represents the complete Semantic Web as a single RDF graph. The library enables applications to query this global graph using SPARQL- and find(SPO) queries. To answer queries, the library dynamically retrieves information from the Semantic Web by dereferencing HTTP URIs and by following rdfs:seeAlso links.
SQUIN is a query interface for the Web of Linked Data. The query system in SQUIN implements a novel query execution paradigm called link traversal based query execution.
LDIF - Linked Data Integration Framework translates heterogeneous Linked Data from the Web into a clean local target representation while keeping track of data provenance.
Semantic Web client for SWI Prolog This is a small prolog program allowing to see the semantic-web as a single graph, and to browse it.
Tabulator AJAR RDF library for Javascript
OpenLink Ajax Toolkit This includes both a Data Access Layer of RDF, SQL, and XML called Ajax Database Connectivity and a collection of RDF aware controls covering: Graph Visualizers, TimeLines, Tag Clouds, Pivot Tables, and more.
Graphite PHP Library for working with RDF. Syntax inspired by jQuery to make it easy and fun to get started consuming linked data.
Graphity LDP Generic Linked Data Platform for consuming & publishing both LD and SPARQL resources.

Crawlers and Data Extraction Tools

ldspider - Open Source Java implementation for a linked data web spider
Anything To Triples (any23) is a library and web service that extracts structured data in RDF format from a variety of Web documents including RDF/XML, Turtle, Notation 3, RDFa, and various microformats. Any23 is written in Java and licensed under the Apache License.
Please refer to the seperate Wiki page about Semantic Web Search Engines.

SPARQL Endpoint Clients

This section lists toolkits that support applications in querying a remote SPARQL endpoint.

C based sparql-client with mysql like shell sparql-query
AJAX Client for SPARQL
SPARQL Client of RAP - RDF API for PHP.
iSPARQL - Ajax-based drag-and-drop visual query builder for SPARQL from OpenLink Software
SPARQL Wrapper for Python
Quick and Dirty SPARQL Browser This simple service lets you poke around inside a SPARQL endpoint.
YASGUI (Yet another SPARQL GUI) SPARQL client with extensive features e.g prefix fetching, syntax highlighting/checking, storing queries

Federated SPARQL Query Engines

This section lists toolkits that enable federated SPARQL queries against a set of SPARQL endpoints.

FedX Federated SPAQRL Query Engine released as open source 2011 by fluid Operatons.
DARQ - Federated Queries with SPARQL DARQ is a query engine for federated SPARQL queries. It provides transparent query access to multiple, distributed SPARQL endpoints as if querying a single RDF graph. DARQ enables the applications to see a single query interface, leaving the details of federation to the query engine (DARQ is not actively maintained anymore).
iSPARQL - Ajax-based drag-and-drop visual query builder for SPARQL from OpenLink Software
Semantic Discovery System provides for federated SPARQL (commercial product)
SPARQL-RW Transparent query access over mapped RDF datasets

Papers

Olaf Hartig, Andreas Langegger: A Database Perspective on Consuming Linked Data on the Web - Paper comparing different approaches/fundamental architectures for querying Linked Data on the Web (data warehousing, query federation, link traversal)
See also Chapter Architecture of Linked Data Applications in Linked Data book.

People Interested in the Area

Richard Cyganiak
Chris Bizer
Yves Raimond
Bastian Quilitz
Kingsley Idehen
Orri Erling
Ted Thibodeau