Welcome to ldfu!

An end-to-end data processing system for data integration and system interoperation with Linked Data.

Linked Programs are Notation3-based specifications for accessing, processing and changing Linked Data, based on logical rules and production rules. You can evaluate Linked Programs with ldfu.

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Data Manipulation

The ldfu system supports high-frequency data access and manipulation via HTTP CRUD methods (Linked Data and Linked Data Platform). Request rules specify how to access data and traverse links. High-frequency access is suitable for Internet of Things/Web of Things scenarios.


The ldfu system includes a streaming query engine for conjunctive queries (Basic Graph Pattern queries) over RDF data.


The ldfu system provides functionality for large-scale data integration, including reasoning with ontologies. Deduction rules specify how to derive new data from existing data. Reasoning supports the integration of data from multiple sources.

Mailing List

For discussion of ldfu use the mailing list at Google Groups.

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Data Sources

The list contains Linked Data sources with relatively high update frequencies.

Frequently Asked Questions

Do you separate link traversal specifications from query procesing?
Yes, we do. Request rules can be used to specify link traversal, while a SPARQL query is evaluated on the resulting data in a streaming fashion. Since 2012.
I have read that Linked Data-Fu is doing remote procedure calls (RPCs). Is this true?
The head of request rules contains HTTP requests. So you could include POST requests that do RPC-style interaction. However, we suggest to use state manipulation CRUD operations following the HTTP semantics. Since 2012.



Linked Data-Fu has been supported by the German Ministry for Education and Research (project ARVIDA, reference architecture for virtual services and applications), the European Commission (FP7 project i-VISION, virtual aircraft cockpit design) and the Office of Naval Research Global.


Added frequently asked questions.
Added links to data sources.
Version 0.9.10 available as part of a closed beta program.
Version 0.9.6 available as part of a closed beta program.
Experiments started (see also: ldfu robots page).
Beta program started.