n-way

Displaying only the similarities between 20 or so files?

Say I've got a directory full of html pages. Their headers and footers are basically the same, but I want to be able to see only the portions of all the pages that are the same. I'd like to call it an n-way merge, but that isn't what it is, it's looking for just the similarities between the header and the footers of all the files. (an...

Are there any n-way diff tools with vertical compare?

I started using diffuse, which you can use to compare multiple files together with, but it's some what useless since you can't horizontally compare lines when you have like 20 files you need to compare together, I was thinking maybe one line from all twenty files displayed horizontally. ...