“In the case of the PDF, what was crucial to its long-term success was the decision by the business that invented it to essentially give its creation away.”

“When is the last time you actually thought about PDFs?” asks Rob Walker in his excellent look into the 30-year-old tool we often take for granted. “The PDF is a digital equivalent to a paper clip or a ballpoint pen — an everyday tool so familiar it seems to have come out of nowhere, yet it’s hard to imagine its absence,” Walker writes.