Fragment, (Snippet, Slice, Brick, Pagelet, Partlet, Slicelet) ?
How about Payload? It is abstract enough and easy to document for both Ajax and
non Ajax requests.
Payload describes precisely, but: for most no-native English speakers,
the first that comes into their mind hearing "Payload" is something
related to "payment" :).
The response might be described as "Content", but that's waaay too
general :(.
I'm trying hard not to use the word "Response" which is already taken by
HttpServletResponse.
The Servlet API is using only "HttpServletResponse" not simply "Response".
SimpleWeb (the high performance async Java web server)
http://sourceforge.net/projects/simpleweb/
seems to use "Response" too, so maybe it's not that bad.
Adrian.