Semantechs Consulting Ltd

Giving meaning to data

We help organisations describe, connect and check their data with open standards (RDF, SPARQL, SHACL, OWL and JSON-LD), so that people and machines can rely on it. We design ontologies and vocabularies, build knowledge graphs, and set up the checks and pipelines that keep them right, with open-source tools or the ones you already use.

Discuss a project Free courses Read the articles

Three free courses: 145 SPARQL queries, 70 SHACL lessons and 76 ontology lessons · The SemOps Manual · Articles on knowledge graphs in practice

Services

Consulting, design and training in semantic technologies and the open standards of the World Wide Web Consortium (W3C). Each service links to work on this site that shows how we go about it.

OWL · RDFS · SKOS

Ontologies and vocabularies

Designing, reviewing and governing the models that give data its meaning, from a first glossary to an OWL 2 ontology a reasoner agrees with, building on upper ontologies such as gist where they fit.

See the Ontology course →

RDF · SPARQL · JSON-LD

Knowledge graphs and linked data

Modelling, integrating and querying data from many sources as one graph, with identifiers that last and provenance you can trace.

Read the articles →

SHACL

Data quality and validation

Shapes that check data on its way in, quality suites for ontologies and graphs, and reports that tell people what to fix.

See the SHACL course →

Pipelines · CI · release

SemOps

Building, testing, releasing and governing semantic systems continuously, as DevOps did for software, with commands you can run today.

Read the SemOps Manual →

In-house workshops

Training

The SPARQL, SHACL and Ontology courses, delivered as workshops for your team.

See the courses →

XML databases · pipelines

XML and publishing pipelines

Native XML databases, and analysis and publication pipelines, for organisations whose content lives in XML.

Discuss a project →

Clients

now EISMEA

Courses

Three free, self-paced courses that share one dataset: the Bookshop Trail, a set of invented bookshops in real British towns. Every lesson opens in the browser in our Turtle Editor Viewer, so there is nothing to install.

145 queries · 18 modules

SPARQL

Querying knowledge graphs, from your first query to property paths, nested aggregation, named graphs, GeoSPARQL and SPARQL 1.2. Every query has been run and checked on three engines.

Start the SPARQL course →

70 lessons · 12 modules

SHACL

Validating data, from sh:minCount 1 to SPARQL constraints, custom constraint components, SHACL-AF rules and SHACL 1.2. Each lesson is shown with the validation report it produced.

Start the SHACL course →

76 lessons · 12 modules

Ontology

Designing vocabularies: meaning, naming, definitions and design principles, then RDFS, SKOS and OWL 2 as one idea. The course ends with an OWL 2 DL vocabulary that a reasoner agrees with.

Start the Ontology course →

The SemOps Manual

SemOps applies to ontologies, mappings, rules and knowledge graphs what DevOps did for software: it is the discipline of building, deploying, governing and evolving semantic systems continuously. The manual links each stage of that work to commands you can run today, and says plainly where the tooling has no answer yet.

I — Why this is hardBusiness case, people and cognition, partners, research-to-industry, GenAI and agents

II — The framePipeline stages, operating model, maturity levels, roles and the toolchain

III — The practiceModel, validate, CI gates, ingest, rules, release and operate, with real commands

IV — The ledgerWhat the toolchain covers, where the gaps are, and a roadmap for adopting it

Read the manual online Download the A4 PDF Source on GitHub

Articles

Longer pieces on knowledge graphs and the problems they help with, written for readers who are new to the technology.

12 November 2026 · 26 min read

Down the Line

Knowledge Graphs for Electricity, from Turbine to Kettle

The power in a kettle comes from no particular turbine. Every statement about where electricity came from is a claim about a pool.

Read the article →

11 November 2026 · 30 min read

The Wood and the Trees

Knowledge Graphs for Forests, Land and People

The trees on a timber lorry have outlived every computer system that ever recorded them. The data about them ought to outlive the next few.

Read the article →

10 November 2026 · 28 min read

Field to Fork and Back Again

Knowledge Graphs for a Good Food Nation

Every bowl of porridge has a supply chain, and for once that is not a metaphor.

Read the article →

All articles Feed

Data Art

A knowledge graph is a set of facts, and facts can be drawn. Our first piece marbles the Bookshop Trail, the dataset behind the three courses, the way a bookbinder marbles the papers inside a book's covers.

A sheet of marbled paper in blues, madders, ochres, greens and rose on a dark ground, with chalk and black hearts inside the stones of colour.

33 shops · 59 events · 33 stretches of trail

Bookshop Trail Endpapers

Every bookshop drops ink where it stands on the map, in the year it opened, in the colour of its specialist genre. Every event of 2025 leaves a ring inside its shop. Then the walking trail combs the ink along its route, which draws the rings into hearts and points.

Point at any colour to see which shop or event made it, or watch the sheet being made one drop at a time, from four SPARQL queries.

See the endpapers →

Tools

Free tools for working with RDF and knowledge graphs. Each runs in the browser, so there is nothing to install, and the courses use the Turtle Editor Viewer for every lesson.

Turtle · SPARQL · SHACL

Turtle Editor Viewer

Write or load RDF and see the model drawn as a diagram beside it. Query it with SPARQL, validate it against SHACL shapes, and share a link that opens with your data loaded. It supports RDF 1.2 and SPARQL 1.2.

Open the editor →

Up to five SPARQL endpoints

RelFinder

Shows how two or more things are connected in a knowledge graph. It searches endpoints such as DBpedia and Wikidata, and your own RDF in the browser, and draws every path between them as a picture you can filter.

Open RelFinder →

Gantt charts · diagrams

Mermaid Editor

An editor for diagrams written in Mermaid, the text-based charting language. Useful for Gantt charts, and for the other kinds of chart Mermaid draws.

Open the editor →

Turtle Editor Viewer guide RelFinder guide

RelFinder is a new version of the RelFinder created by Heim, Hellmann, Lehmann, Lohmann and Stegemann. Its guide explains how to use it and credits their work.

Contact

Please get in touch to discuss your project. To see how we can help you, email enquiries@semantechs.co.uk, or choose one of the subjects below.

Consulting

Discuss a project

Ontologies, knowledge graphs, data quality or SemOps: tell us about your data and what it needs to do.

Email about a project →

Training

Arrange training

The SPARQL, SHACL and Ontology courses, delivered as workshops for your team.

Email about training →

Courses · manual · tools

Ask a question

Questions, corrections or suggestions about the free courses, the SemOps Manual or the tools.

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