Per recommendation, moved this new link to "Test Data" section since data contained by the API is "dummy data" conforming to the FHIR spec.

Publicly available test data conforming to the Fast Healthcare Interoperability Resources (FHIR) spec.

Another Quotes API. It provides various options to get quotes and perform operations like Update, Delete, Up-vote, Favourite, Hide, Tag on a quote. Random Quote doesn't require API key. You can request quotes from a specific category as well.

This change adds a 'Jokes' API to the "Games and Comics" section.

Adding QR code API to development section

Link has been dead since early August, removing dead service

Link has not been live in over 4 weeks, removing dead service.

Change Czech national bank´s category

Removed the extra |

PiXhost like imgur is a image hosting service and is free to all users. Some people who have slightly more graphical content that gets rejected at imgur switch to PiXhost because it has more lenient rules. It also has an API that is not known.

From their website:

"Welcome to the PiXhost API!
You can use this API to upload images, covers or galleries.
The following image formats are supported: image/gif, image/png, image/jpeg. Maximum image size is 10 MB.
In case you have any ideas, questions or issues, feel free to contact us at: admin@pixhost.org.
Old API users: We recently enforced https, please update your scripts."

Adding https://coinbin.org/ (from @kennethreitz) to the list.