Open Source at the City of Amsterdam

The City of Amsterdam is both a user and contributor to and developer of, Open Source projects.

Our projects range from a 360° panorama processing system to an OAuth 2.0 server written in Go.

We publish the source code to our projects on We publish the source code under Open Source licences (most commonly MPL2.0) that allows anyone to view the source and to copy our source code to use it in their projects. We do not provide any warranties or guarantees on the reuse of our source in others’ projects.

We are looking forward to collaborating with you!

Why the City of Amsterdam uses, contributes to and develops Open Source

Being a part of the Open Source ecosystem – in which we are both a user and contributor – is an essential enabler to the development of our digital services.


We live in a time where most of the problems we are facing as a city – including societal, technological, mobility, growth and climate – are too large to solve on our own. We need to collaborate with other cities, governments, businesses and individuals to solve these problems. Meaning we are sharing our knowledge as much as possible, so that we can learn from our peers, and can collaborate on solutions.

Using and developing Open Source and actively participating in its ecosystem enables us to create valuable collaborations that would otherwise not be possible.


Our software processes sensitive data and it informs us in making crucial decisions about citizens. Using and developing Open Source is essential in providing the security we need. If you do not know what is in the software you rely on, you cannot tell there is no backdoor.

We play an active role in improving the security of Open Source projects we depend on, and we invite the broader community to audit the security of our projects, as well as suggest improvements.


The software we work with and produce handles the often private information of citizens and companies. Using and developing in Open Source provides a necessary level of transparency for our users and clients.

We put a lot of effort into providing high quality internal and Open Data. Using and developing Open Source and being transparent about how the data we use for decision making is created and utilised gives it the context it needs to be useful and reliable.


Participating in the Open Source ecosystem, both as a user and as a developer, means that finding solutions to problems is always a community affair that involves users, contributors and the core developers of a project. The community helps by quickly resolving simple issues as well as adapting the code to solve more complex issues. Fixing problems together means every problem and its solution leads to better code for every user.

Reliability and Maintainability

Using and developing Open Source means working with a diverse community in different circumstances to review, test and maintain the code at the core of our services.


Using and developing Open Source software enables us to have flexible control over our processes and full access to our data. The flexibility and access enable a more flexible process in which we can develop new solutions quicker and with higher effectivity.

Open Source enables us to work with a wider variety of suppliers and freelance developers, meaning we can eliminate vendor lock-in as well as work with better, smaller or more specialised suppliers.


Developing Open Source projects means developing for reuse. Open Source projects are scalable and interoperable.

Developing in the open also allows for other opinions – inside of our organisation and outside – to help adjust the direction of a product to maximise its usefulness to the community it serves.

If one of our projects is successful it can – relatively easily – be replicated or changed to be implemented in a different circumstance.

If one of our projects or parts of one of our projects is reliant on another project we want to replace, the principles of reusability make sure we can easily switch.


Many developers prefer developing an Open Source project over a closed source project. Using, contributing to and developing Open Source projects means working at the City of Amsterdam is a lot more attractive for those brilliant, civic-minded, career developers out there.