HASTUschon is a German marketplace with over 10 million products that can also bought through Bitcoin Payment. The site also lets users participate in auctions such as normal bid oder fixed price auctions. The API is for accessing site data on shopping, bitcoins, product information, etc. This data can be integrated into third party web sites and applications. The API uses HTTP calls and responses can be formatted in XML, JSON and Text.
Documentation available as an open Google Doc at: https://docs.google.com/document/d/1qqxXtVg7eVXHXYpEMIa2Y2cz6xq0t8GXuKXmpKDrfPY/edit?hl=de&authkey=CLnAp8oO