Talli,
An interesting set of definitions for "Enterprise application frameworks" and OACS would be one for Web apps is in:
Building Application Frameworks : Object-Oriented Foundations of Framework Design by Mohamed Fayad (Editor), Douglas C. Schmidt (Editor). Wiley
and
Implementing Application frameworks by the same authors.
These books (it is really a trilogy) has a lot on the software engineering side but also business arguments like the ones discussed here. Amazon has the PDFs for the preface that provides some of the definitions.
cheers
Rafael
