dct

Voyager is the name RAF use: http://www.raf.mod.uk/equipment/voyager.cfm

All the contributors have rather cryptic usernames: https://github.com/orgs/gchq/people

Also featured in Sharpe's Tiger (https://en.wikipedia.org/wiki/Sharpe's_Tiger)

The police still use them a lot: http://www.bbc.co.uk/news/magazine-20556330

May be the number of people who took this course and found it interesting?

since 1971