Where can I find a list of cities with public bicycles available in Europe?

Question

Whenever I visit a city I find traveling by bicycle very convenient. It's very flexible and you get to see the city in a very friendly way.

I was wondering if there is a website or other resource that lists cities in Europe where public bikes are accessible also to tourists.

Note: I am not referring to companies renting bikes. I am really referring to public systems like exist in Paris or Copenhagen where everyone can use bikes. If the list contains the requirements to use the bicycles that would be a big plus. Eg.: In Paris, if I remember right, you need a Credit Card.

Answer 1

Wikipedia is your friend with an entry on Bicycle sharing systems.

Answer 2

This is maybe not exactly what you're looking for, but fluctuo^{not affiliated} is a shared¹ mobility aggregator that provides a map where it lists all available shared¹ vehicles (bikes, scooters, mopeds) on a location.

Additionally, there is a Github repository that lists bike sharing systems that publish their information in accordance with the General Bikeshare Feed Specification (GBFS), which is a standardized data feed for shared mobility system availability.

^{1: It's actually all rental mobility, as one always has to pay for the service of using a vehicle. It's just that the vehicle is not rented out at a single location but on different locations in an area.
Clever marketing has spread the term "shared mobility" to give it a friendly and less profit oriented vibe.}