1. Wordpress Web Service
WordPress Web Service is used to access WordPress resources via WSDL and SOAP
2. WP Simple Web Services Simple WordPress Rest Web Services. Add JSON REST web services to your WordPress website with a few clicks.
3.Brickset API
Implementation of the Brickset Webservice. Includes methods to get set data from Brickset as well as pre- formated methods to display set data. This is not an official Brickset.com offering.