The "opposite of ediff"

[Dave Abrahams]

I often am trying to pick out common regions from multiple files.  This
cries out for the "opposite of ediff": something that will walk me
through the common areas of files that are substantially different and
show them to me with their differing surrounding context.  Ediff turns
out to be pretty bad at this.  I can generate a list of common regions
using simian, but what I really need is an interactive browser.  Any
ideas?  Is this a problem you've already solved?

Thanks,

-- 
Dave Abrahams
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