Web developers and others involved with Web 2.0 are excited about the idea of creating new Web applications by 'mashing together' different data sets. A typical mash, also called a hack, involves a feature like Google maps linked to a data set that benefits from display in a geographical context. Amazon, the Internet retailer, took the mashing concept somewhat further by opening its Alexa search index to third parties. This allows anyone to create Web applications that can incorporate the Amazon search engine. They can do so at relatively little cost, and then link the application to Amazon's e-commerce engine using the company's Web services platform. None of the application concepts is new, but the barriers to creating such applications are disappearing at a rapid rate. Developers may still want to license similar tools in order to create more robust applications, but many business applications can be created using services like Google Maps or Alexa. Many applications can be created using Asynchronous JavaScript (Ajax) and XML. Ajax and technologies like Really Simple Syndication (RSS) and Web services represent the real potential of XML, which provides developers with a data-neutral file format. New applications like Microsoft Office 12 will ultimately make XML the dominant file format. When this occurs, applications will act more like data containers than places where vendors hold data and lock customers into their platforms.