alt Hacker NewsI don't recall it in Frankfurt last summer, but it was definitely going earlier this month. Though, they've got a weird security setup for some of the gates, so I'm sure it varied from gate to gate. Dublin and Edinburgh have had it for a while too, Dublin since last summer. Really speeds up security.
Yeah, even small airports like Belfast City have had it for the past couple of years. Other London area airports (Luton, City, and Gatwick - not sure about Stansted) have had it for about as long, too.
Heathrow's definitely a straggler - I'm assuming it was a more difficult project for them due to their sheer size.