FYI: The grep in homebrew/dupes is not a newer version of the grep provided by OSX. OSX grep is the BSD variant, hb/dupes provides GNU grep. I am always shocked by how poorly BSD grep performs compared to GNU grep. I think you need to provide the `--default-names` option in order to use GNU grep in place of BSD grep.
> What is the difference between the cask installation suggested in the link and the cask installation procedure suggested on the cask home page?
Two differences. One is that we moved to an org repo, so the first form is relying on the github redirect from the move. The other is that the second form relies on the semi-recently introduced "auto-tap" syntax in homebrew.
Functionally they will get you to the same place (we've got code to notice that your remote is pointing to the old repo location and update it), but the second form is newer and cooler. ;)
