Developer Tools
Access the OTN open APIs and Open Source Code components.
OTN Metadata Profile

OTN metadata is exposed using GeoDCAT-AP for geographical data and DCAT-AP for non-geographical data. These are both European standards based on the W3C DCAT standard for describing datasets. Geographical data is actually annotated with INSPIRE metadata, which is a European standard only for geo data. GeoDCAT-AP allows mapping INSPIRE metadata to the DCAT format. Further details on how OTN deals with metadata can be found in section 3 of the first OTN innovation white paper which can be found here.

Please visit the following links for information about the afforementioned standards:

How can I re-use data?

All datasets available in OTN can be downloaded using the relevant 'Download Dataset' button at the details page of a dataset, e.g. Public bike stations "Vélo" | Antwerp. The download button can be easily seen at the bottom of the screenshot below:

Map Compositions can also be shared using a unique link provided by the tool. Simply click on the share icon next to a map composition and get a shareable/embedable link of the selected map composition as depicted in the figure below:

OTN Page in GitHub

The OTN Hub is built upon Liferay using a number of custom portlets which integrate visualisation modules and other utilities (e.g. marketplace) used in the context of a Hub. The code repository of the OTN Liferay instance is available at

OTN Mobile App [Beta]

OTN Mobile Version allows users to search for existing datasets, create map compositions and share them on social media. Please note that it's still in beta status with more functionalities (e.g. save of map compositions) to come! The code repository of the OTN Mobile App is available at


WebGLayer is a JavaScript library focused on fast interactive visualization of big multidimensional spatial data through linked views. The library is based on WebGL and uses GPU for fast rendering and filtering. Using commodity hardware the library can visualize hundreds of thousand of features with several attributes through heatmap, point symbol map. The library can render the data on the map provided by third party libraries (e.g. OpenLayers, Leaflet, GoogleMap API). The library's page can be found at and the source code at this code repository

A visualisation of the UK car accidents data using the library can be found at


The RDF Mapping Language (RML - provides a solution to model domain-level knowledge derived from multiple heterogeneous data sources, in a scalable, integrable and interoperable fashion as RDF, the prevalent framework for Linked Data. RML formalises mappings which define how data from a specific data source is mapped to RDF triples. These mappings, which are constructed using RDF triples, are interpreted by a RML processor to produce the actual RDF for a data source. RML is defined as a superset of the W3C-recommended mapping language R2RML, that maps data in relational databases to the RDF data model. RML extends R2RML's applicability and broaden R2RML's scope to define mappings of data in other formats too.

Linked transport data and DATEX Format

Click on the link above and find out more information about transforming and managing transport data into Linked Data via the use of DATEX format. Demo use cases, examples and relevant tools for developers can be retrieved for further research and development of new ideas and applications!