I need a diff tool for comparing different versions of the same excel
document. Surprisingly hard to do. Excel has built in change tracking,
but that's no help if you didn't turn it on and now somehow have two
different versions of the same spreadsheet.

A lot of products out there claim to do it, but they don't quite work.
Synchronizer at http://www.synkronizer.com/e/infos.html worked best, 30
day trial, 149 for the most expensive version; there are also lighter
weight versions for cheaper. Looks like the best bet to me.

Component software has exceldiff, but that only identifies differences
in values, not in formula. Ie, if the formula is different but the
value is the same, doesn't identify differences. Workshare professional
delta view also was a dissapointment; seems to require integration with
the built in excel version tracking; my eyes glazed over trying to
understand it.

Diffdoc from softinterface was another dissappointment.

So, Synchronizer seems to be the best bet. Identifies values and
formulas, new rows, new columns, output is in excel format. The only
thing I wish it had was some way to identify format changes.

Well, that's it; hope that helps someone. If I missed something obvious
with regards to diffing and excel, chime in, folks, wouldn't surprise
me at all. :)