Need to send a file most people won’t need to edit? Send a file that’s both editable and final form at the same time, a kind of Schrödinger’s Document – a Hybrid PDF.

One of the scourges of e-mail is file attachments, and particularly those from people sending files made by their newly updated word-processor or presentation programme that half the people receiving it can’t open. While proprietary software vendors love this errant behaviour (it keeps up the pressure for people to re-purchase software they don’t really need so they can read other people’s work – AKA “upgrades” – or to subscribe to an online service that keeps them trapped), it’s really anti-social behaviour.