Real diff application or tool for OpenOffice.

Problem: 
The way I use open office, I get a 
real problem when using the ”compare files” feature: 
I usually have to save the documents that I 
send in Microsoft *.doc format, but I usually work in the OO *.sxw format.

Comparing two files 
in *.doc and *.sxw format does not work properly. i.e. almost everything differs between the two 
files. It is extremely sensitive for insertion of empty lines, which in my opinion makes no 
difference. Or at least I would like to be able to make it ignore line insertions.

Earlier i 
used to use tools like the CSDiff application for similar work, but that one is not compatible with 
OO, and it does a fairly similar work as OO anyway -  although I get a few more options like show line 
numbers and only differences.

I would like a ”diff” application or tool, where I get the two 
files side by side, I can choose to filter what I like to compare, for instance, just formatting is 
usually not that important, I get to see (virtual?) line numbers, to determine if one of the 
documents have changed page size etc. I would like to compare just spelling and grammar, to decide 
only to show what differs between the files, where the tool should be smart enough to notice that 
the exact same text appearing at a different place is no difference etc. (unless I have specified 
that I want to detect that type of differences).

It would be even better if it worked for the 
excel type of files as well, although I imagine that would be really hard to implement.

The 
model application I think of here (the way I would like it) is somewhat similair to ExamDiff, that I 
use for compairing versions of source code.