Datafiles binary portable?

This is probably a silly question, but are the database files binary portable?
eg could I take datafiles from a Sparc and copy them to an Intel machine,
or would the endianness differences kill me?

I expect the answer to be "funny man!  Of course not!" for reasons of speed
(native interger handling being quicker than forcing network-endianness,
for example) but you never know...

How about cross OS (eg from Linux Intel to Windows XP, or from Solaris Intel
to Linux Intel)?

(I almost expected this to be a FAQ, but I didn't see it there).

--

rgds
Stephen