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How it works

We provide tools to allow journalists to extract data from their stories, expanding the scope of their creations. Also, these tools can add live graphs that evolve with the addition of new data sources.




write your content in your own style.       


Ontag provides an API to access data extracted from your article.


Ontag identify entities in your story highlighting text.


Users establish relations among the detected entities.


Ontag connects entities such as people, places, dates to linked data

Your content now has produced data beyond your story, effortless! This data could be use to keep researching, producing data visualizations and more.

Try it yourself

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Initiators and Partners

ONTAG is an initiative of the Common Action Forum and counts with the partnership of the Ontology Engineering Group of the Polytechnic University of Madrid

Common Action Forum

The Common Action Forum (CAF) is a transnational, non-profit organization established in Madrid, Spain in 2015. It acts as a global network, bringing together prominent and emerging experts from diverse backgrounds, including academia, politics, media, civil society, the arts and journalism.

CAF’s mission is to establish and encourage independent platforms of cooperation, research, innovation and advisory in order to shape alternative solutions and empower global citizens to address today’s challenges. The Foundation advocates for the collective design of global strategies and new frameworks that champion progressive values.

Ontology Engineering Group

The Ontology Engineering Group (OEG) is based at the Computer Science School at Universidad Politécnica de Madrid (UPM). It ranks eighth among the two hundred research groups from UPM and it is widely recognised in Europe in the areas of Ontology Engineering, Semantic Infrastructure, Linked Data, and Data Integration. Our main research areas are: Ontological Engineering, (Social) Semantic Web and Linked Data, Natural Language, Semantic e-Science and the Future Internet.


Carlos Saito

Computer Engineer focused on developing modern applications using web technologies, with interest in frontend and data analysis. Developer in Ontag.

Cristian Hernandez

Expert in spatial analysis and data visualization. He works as a consultant for nonprofit organizations and startups in Europe and Latin America. Cristian is currently leading a citizen data science project on light pollution called “Octal”, part of the Stars4All Program (EU funded). He has trained people in data science methods and visualization during the last two years.

Esteban Gonzalez

Software engineer and computer scientist at the Ontology Engineering Group (OEG), he had an internship in EADS and worked in DEIMOS-SPACE as software deliver. He also participated in the european projects GLORIA - an open robotic telescope network teleoperated by citizens, and STARS4ALL - a platform for fighting against light pollution problem.

Maribel Mateos

Journalist specialised in Multimedia Journalism from Complutense University of Madrid, with digital marketing studies through the Madrid Chamber of Commerce and Industry, and Google. Over 6 years of experience working in corporate communications and in different roles across the media industry.

Rafael Heiber

Rafael Heiber is the Co-founder and Executive Director of Common Action Forum. He is geographer and holds a PhD in Sociology from the University Complutense of Madrid. His work focuses on territorial and political implications of sociotechnical systems.

Open Source

Ontag is open source software. You can collaborate and use it for free:

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