Linked Open Data. Connecting heritage.
Collections contain a wealth of objects, people, places, and stories. With Linked Open Data, you make their interconnections understandable for systems and usable outside your own organization. We help heritage institutions take that step practically and carefully.
objectA stable URI
as a starting point
Information becomes more valuable when you can connect it.
A painting in a museum, a letter in an archive, and a person mentioned in another database can all be about the same creator. Often, the individual systems are unaware of each other.
Linked Data uses recognizable, persistent references and standardized relationships to make such connections explicit. Open means the data is available for reuse under certain conditions, for example with an open license.
Not everything needs to be public. Even if certain data remains protected, you can still apply the principles of Linked Data. This creates a technical foundation that lasts longer than a single website or system.
Not another database where everything must converge, but a network where sources can find each other.
A search query can also include related people, places, or concepts.
Shared definitions and identifiers make data exchange easier.
The same data can be used for research, public platforms, and digital services.
From fragmented collections to new possibilities.
LOD is not an end in itself. The added value lies in what you make possible with well-connected heritage information.
Connecting collections
Link objects, creators, places, and themes across institutions without physically merging all data.
Better findability
Make context and meaning machine-readable, so information is easier to discover and interpret.
Sustainable reuse
Publish using stable references and reduce dependence on separate exports or a single vendor.
Room for innovation
Create a usable knowledge base for research, public platforms, visualizations, and carefully applied AI.
Three building blocks. One shared meaning.
The technology sometimes sounds abstract, but the principle is simple. You state in a fixed, machine-readable way what something is and how it relates to other things.
1. Identifiers
An object, person, place, or concept is given a unique URI: a web address that refers to that specific thing. With persistent identifiers, references remain usable even if the underlying software changes.
More about PIDs ↗2. Relationships
With standardized properties, you describe the meaning of a connection. For example: this work was created by this person. In RDF, such a statement is called a triple: subject, predicate (relationship), and object (value or reference).
Linked Data concepts ↗3. Connecting sources
You link to existing concepts and authoritative sources, for example via the Termennetwerk, RKDartists, or a geographical terminology source. This way, systems recognize they are talking about the same meaning.
View the Termennetwerk ↗From text field to meaningful relationship.
A fictional collection object refers not just to the text "Mieke Jansen," but to a recognizable person identifier. Another institution can refer to that same person, allowing the information to be connected.
To the right, you can see how such a relationship can be described in JSON-LD. This is a simplified example, not a full NDE publication profile.
{
"@context": "https://schema.org",
"@type": "CreativeWork",
"@id": "https://example.org/object/123",
"name": "Foto van de markt",
"creator": {
"@id": "https://example.org/persoon/45",
"@type": "Person",
"name": "Mieke Jansen"
}
}How do you publish Linked Open Data?
The best publication strategy depends on your data, the target audiences, and what your current systems can handle. Two routes can complement each other.
Schema.org & JSON-LD
With the schema.org vocabulary and the JSON-LD format, you can publish object information in a structured way, for example on object pages on your website. This helps machines interpret the information.
An accessible start, especially if the collection management system already supports this publication.
- Suitable for showing structured metadata directly at the source.
- Helps with semantic exchange and can support findability.
- For NDE connection, use the corresponding heritage profile and persistent URIs.
RDF & optional SPARQL
Do you want to connect complete datasets or enable advanced queries across multiple sources? Then we publish data as RDF, for example via files, resolvable URIs, or a suitable API.
A SPARQL endpoint can additionally support complex search queries over RDF data. Useful for research and data-driven applications, but not mandatory for every LOD publication.
- Suitable for sustainable exchange of larger or richer datasets.
- Supports relationships between people, collections, places, and concepts.
- Allows advanced querying if functionally required.
No larger project than necessary. But a solid foundation.
We first look at the goal, the available data, and the capabilities of your current systems. From there, we work specifically toward a publication that is technically sound and can actually be used.
Defining goal and target audience
Is it about findability, data exchange, research, a public platform, or a combination?
Reviewing sources and quality
We examine metadata, collection management systems, existing APIs, and any restrictions on reuse.
Establishing entities and URIs
We determine how objects, people, places, and concepts can be persistently identified.
Modeling and connecting
We choose appropriate standards and terminology sources and define what the relationships mean.
Publishing and validating
From JSON-LD to dataset publication: we build, test for quality, and document the publication.
Application and management
We connect the data with websites, applications, or research and set up maintenance and further development.
This can start with a defined technical exploration or proof of concept. It doesn't have to become a completely new collection platform right away.
Connecting heritage information starts with real applications.
These projects show how we work on collection access, data linking, and digital accessibility. Not every project is automatically a full Linked Open Data publication.
Museum Vlaardingen
For Museum Vlaardingen, we are developing a digital environment in which objects from the collection are connected to stories. A link with Atlantis provides access to object data. In the technical implementation, we take NDE principles and Linked Open Data into account.
Discuss collection access
Stichting Wijkcollectie
For Stichting Wijkcollectie, we built the CMS and public platform that allows Rotterdammers to discover neighborhood stories via an interactive map. The platform is designed with attention to the principles of the Netwerk Digitaal Erfgoed.
View the platformDiscover our public platforms, story routes, collection integrations, and interactive museum experiences.
Further reading on connected data.
From the technical foundation to the concrete agreements relevant to Dutch heritage institutions.
Technical questions, clear answers.
Linked Open Data doesn't have to start complicated. These are the questions that often come to the table first.
Do we need to replace our current collection management system?
Usually not. First, we look at what the system itself supports: stable identifiers, exports, APIs, and any publication as linked data. Often we can start with an additional integration or publication layer.
Is JSON-LD the same as Linked Open Data?
No. JSON-LD is a format for Linked Data. It only becomes truly connectable and reusable when you also apply consistent URIs, meaningful relationships, accessible data, and appropriate terms of use. Schema.org can help with this, especially in combination with the NDE heritage profile.
Do we need a SPARQL endpoint?
Not always. SPARQL is valuable when you want to ask complex questions across RDF datasets. You can also offer Linked Data via resolvable URIs, files, or other suitable publication methods. The required access depends on the users and applications.
Does all data have to be public?
No. The distinction between Linked Data and Linked Open Data is important. Where reuse is not permitted, you can protect data or only publish certain metadata. Rights, privacy, and agreements with source holders determine what is possible.
Does this align with NDE-compatible working?
Yes. Within the Netwerk Digitaal Erfgoed, Linked Data, persistent identifiers, standardized terms, and shared publication agreements form an important foundation. In the Netherlands, you align with the NDE schema.org profile and relevant NDE facilities, among others.
What do you want to connect with your collection?
From an initial inventory and JSON-LD on object pages to a sustainable LOD architecture. We help think about the right route and can also realize the technology. Without unnecessary complexity.
← Back to Digital HeritageDiscuss your challenge.
Tell us about your collection, systems, or plans. Then we'll look together at the most meaningful next step.
Schedule an introduction