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.