<p>If you have two versions of the same report (.rpt) and you want to establish what the exact differences are, what is the best way to go about this? I've seen some commercial tools to do this, but I'm not too interested in forking out cash for something that should be relatively straight forward. Can I hook into the Crystal API and simply list all of the properties of every field or something? Please someone tell me that there's an Open Source project somewhere that does this... @:-)</p>

<p>@Kogus, wouldn't diffing the outputs as text hide any formatting differences?</p>

<p>@ladoucep, I don't seem to be able to export the report <em>without</em> data.</p>

One helpful technique is to output both versions of the report to plain text, then diff those outputs.
You could write something using the crystal report component to describe every property of the report, like you described.  Then  you could output
that
to text, and diff
those
.  I'm not aware of any open source tool that does it for you, but it would not be terribly hard to write it.
@question in the post:
Diffing the outputs would only show formatting changes if the
relative
positions had changed.  For example, if i had this:
before:
First name, last name, addresss
after:
Last Name, First Name, Address
Then that would show up as a difference.
But if I had just bumped the address column over a few pixels, or changed it from plain text to bold, then you are right, that would not show up.