Excelente documento de Host Access Transformation Services.
En mi blog tengo un par de documentos sobre HATS.
Cuando era joven participé en varios proyectos de HATS, me encantaba este producto, muy fácil de implantar y lo más importante, no es necesario tener ningún conocimiento especial para empezar a usarlo.
He creado una nueva etiqueta en mi blog "Hats", para ir añadiento todos los documentos relacionados con este producto.
Como disfrutaría haciendo un proyecto para Hats mobile, pero claro, only for iPhone, of course.
El peazo iPhone tiene un enlace al documento.

With IBM® Rational® Host Access Transformation Services (HATS), access to host applications can be modernized and delivered to users without any impact to the existing, proven host applications. HATS does this by dynamically transforming and delivering 3270 applications running on IBM® System z® platforms and 5250 applications running on IBM® i® platforms to web, portal, or rich-client users and by exposing key business processes and data as web services. Using HATS, you can create web applications and rich-client applications that provide an easy-to-use graphical user interface (GUI) to improve usability and increase reuse of 3270 and 5250 host applications. You can develop HATS web applications, including portlets, with an interface that matches a company's web or portal GUI standards, and users can access them through their web browsers. HATS web applications can also be developed to provide access to host applications from mobile devices, such as cellular phones, data collection terminals, and PDAs.