In 1997, a team of engineers hid an entire flight simulator inside the code of Microsoft Excel as an unlisted "Easter egg" — and to this day, it remains one of the most sophisticated pieces of hidden software ever secretly shipped to millions of corporate computers (opens in new tab)

Somewhere on the hard drives of millions of corporate computers in the late 1990s, buried inside a piece of software almost universally used for tax returns, sales forecasts, and quarterly reports, there was a small 3D world. You could not reach it through any menu. You could not find any reference to it in the […]