This should at least give you an overview of differences among unix shells http://hyperpolyglot.org/unix-shells

It'd be cool to see some kind of interactive exercises like (Vim Interactive Guide) http://www.openvim.com/ and (Git) https://try.github.io/

How about a version of VIM Adventures[1] but named instead BASH Adventures?

[1] http://vim-adventures.com/

I wish there was a ranking like this with only reviews from engineers counted as that would be more relevant for me.

I've only had luck with Apple Pay in Trader Joe's and Panera so far. Discover is doing 10% cash back for payments made in Apple Pay until the end of the year so I've been trying hard to find any stores that accepts it, but couldn't find that many places. If it were accepted by more retailers (e.g. CVS, Stars Market), I can see it being more widely used.

By the way, I remember Target, CVS, and some other retailers were working on their own payment system using QR code. I wonder what happened to it.

Upvoted for the headsup on the Discover card alone. Every time I've tried to add my Discover card to my Apple wallet, I've been told that Discover does not yet support it.

I would use Apple Pay 100% of the time if it were available. In particular, I long for the day when you can pay with Apple Pay at restaurants so you don't have to hand off your credit card to someone who disappears with it and comes back later.

This Christmas I promised to help set some relatives up with Apple Pay and show them how to use it.