Violet this week announced what it says is a "unified API for anything on the internet." The idea is to make it easy for people to buy whatever they want, no matter where they see it on the web, without requiring them to backtrack or hop through ecommerce sites across the internet.
With Lemonade Stand, users can search for things to buy in a location-based manner, or add their own listings of things they wish to sell. The application is currently available as a client for Android, with a possible Windows Phone 7 version on the way soon as well, from a 3rd party developer that released an early version. Its Lemonade Stand API allows other developers to either code their own clients or use it in mashups.
CARDFREE has opened its order-ahead API for third party integration. Third parties can include order-ahead and payment processing in their existing apps that include support for complex menus, upselling/cross-selling, combinations and much more. The API works seamless on mobile and web.