This document discusses the concept of banks becoming platforms through the use of open APIs. It argues that APIs can help banks overcome legacy IT systems and drive innovation by allowing third party developers to build applications and services on top of bank data and services. The Open Bank Project is presented as an open source project and API that banks can implement to become more open and accessible to developers. Examples of applications that have been built using the Open Bank Project API are provided like accounting and financial analytics tools. The benefits of APIs for banks, developers and customers are outlined.