Apache MyFaces Orchestra aims to provide a simple way to combine a web-framework with a persistence layer. Typically, an Apache MyFaces Orchestra stack might combine JavaServer Faces, Spring and a JPA implementation like Toplink, Hibernate, etc.
The underlying idea is to provide long persistence sessions to the web-developer - this is done by associating these sessions with a conversational context.
The conversational context is opened when the bean configured for this context is first loaded. It can be manually closed by the programmer, plus a time-out can be configured as a global parameter.
The Google Web Toolkit (GWT) has attracted a lot of attention lately as a way to make it easier for developers to add AJAX Web 2.0 features to their applications. Like other approaches, the designers of GWT have tried to insulate developers from having to deal with the underlying JavaScript, which implements these features. GWT achieves this goal of simplifying the creation of advanced client-side JavaScript widgets by generating them from Java code.