Hemingway had it easy. Writing books in the 1920s involved little more than pen and ink. The period’s most advanced tool was a Remington typewriter. No such luck for the modern author. Yes, we have access to a wealth of information unthinkable a few decades ago. But we confront a problem unknown in Hemingway’s day: the proliferation of software designed to help to organise our thoughts before sitting down to write.

Because my books weave together multiple disciplines—one was even subtitled “the connected lives of ants, brains, cities, and software”—and in part because I write about technology, people often ask me how I write. As it happens, I have developed an idiosyncratic writing system. My basic tools, like word processors, have varied. (I swore off Word after one book, and used another programme for the next two before returning sheepishly to Microsoft.) But the one constant is a truly ingenious