TaxServer
Reference
The API description included with the TaxServer Docker container contains a complete reference, along with a tutorial which shows how to develop a Javascript client which accesses its services.
On a machine which has Docker installed, enter:
docker run -p 8000:80 calibertechnology/taxserver
You can then access documentation by directing your browser to http://localhost:8000
More information about this container is available at the Taxserver Docker hub.