Phil at Loosely Coupled was kind enough to send me a definition of "composite application":
Here’s Loosely Coupled’s definition:
An application built by combining multiple services. A composite application consists of functionality drawn from several different sources within a service oriented architecture (SOA). The components may be individual web services, selected functions from within other applications, or entire systems whose outputs have been packaged as web services (often legacy systems).
It’s a favourite term of Gartner’s Massimo Pessini, the man who also gave us ‘ESB’
I had great conversations on this topic recently with some really smart people. Unfortunately we were all rather drunk and I don't remember what we concluded - although I think it had something to do with molecules. Ok, this in only partially true. We basically agreed that the definitions of composite apps was still too loose (SOI, SODA, integration at the glass, how many of the NFR's need to be addressed by services, how much of the app needs to be SO enabled, etc.) Bottom line is that we need to move to a 'definition by constraints' view.