The Stack


This is Version 3.0 of the LOD2 Stack, which comprises a number of tools for managing the life-cycle of Linked Data. The life-cycle comprises in particular the stages

  • Extraction of RDF from text, XML and SQL
  • Querying and Exploration using SPARQL
  • Authoring of Linked Data using a Semantic Wiki
  • Semi-automatic link discovery between Linked Data sources
  • Knowledge-base Enrichment and Repair
Interlinking



LIMES implements time-efficient approaches for large-scale link discovery based on the characteristics of metric spaces.



 SILK
Data publishers can use Silk to set RDF links from their data sources to other data sources on the Web.


    SILK
Silk can be used as an identity resolution component within
applications that consume Linked Data from the Web in order to augment
Web data with additional RDF links.



 Sieve
Sieve allows Web data to be filtered according to different data
quality assessment policies and provides for fusing Web data according
to different conflict resolution methods.
Classification
Enrichment



DL-Learner is a tool for learning concepts in Description Logics (DLs)
from user-provided examples. Equivalently, it can be used to learn
classes in OWL ontologies from selected objects. The goal of DL-Learner is to support knowledge engineers in constructing knowledge and learning about the data they created.
Quality / Analysis



The ORE (Ontology Repair and Enrichment) tool allows for knowledge engineers to improve an OWL ontology by fixing inconsistencies and making suggestions for adding further axioms to it.
Evolution / Repair



LODrefine

LODGrefine is based on a powerful tool Google Refine, but customized for the needs of LOD2 project. While Google Refine itself allows to load data, understand it, clean it up, reconcile it, and augment it with data from Freebase or any other (registered) service, LODGrefine has already integrated extensions, which provide additional functionalities especially suited for working with Linked Open Data.
Search / Browsing
Exploration



The sig.ma service was created as a demonstration of live, on the fly Web of Data mashup. Provide a query and Sig.ma will demonstrate how the Web of Data is likely to contain surprising structured information about it (pages that embed RDF, RDFa, Microdata, Microformats)

Spatial Semantic Browser
An application for browsing and exploring geographical RDF data on a map.


CubeViz
CubeViz allows visualization of the Data Cube linked data representation of statistical data. It has support for the more advanced DataCube features, such as slices.

Facete
facete is a spacial semantic browser
application, with a focus on faceted browsing.

more tools
  • lod2webapi by TenForce
Extraction

Virtuoso Sponger

 





 UI







D2R



R2R



CSVImport



other tools: VALIANT by Tenforce
Storage / Querying


Virtuoso 7 RDF Store
The open-source edition of Virtuoso, is the basis for the LOD2 Stack's knowledge store. Virtuoso 7 is now a column store, increasing the performance of SPARQL queries significantly.

SparQLed
SparQLed is an interactive SPARQL editor that provides context-aware recommendations, helping users in formulating SPARQL queries.
 

sparqlify
A scalable SPARQL-SQL rewriter, allowing you to query an SQL database as if it were a triple store.

SIREn
A Lucene plugin that allows you to efficiently index and query RDF, as well as any textual document with an arbitrary amount of metadata fields.


more tools
  • sparqlproxy by AKSW
manual revision
authoring




Ontowiki enables intuitive authoring of semantic content, with an inline editing mode for editing RDF content, similar to WYSIWIG for text documents.



RDFAuthor
The system is able to extract structured information from RDFa-enhanced websites and to create an edit form based on this data.





PoolParty is a thesaurus management system and a SKOS editor for the Semantic Web including text mining and linked data capabilities. The system helps to build and maintain multilingual thesauri providing an easy-to-use interface.



Additional components





The 'lodms' application allows the user to quickly set up pipelines for transforming linked data through the use of its many extensions. It also allows operations for extracting rdf from other types of data.