In September 1985, Microsoft introduced Excel, an electronic spreadsheet program that revolutionised the way we organise and analyse data.

With its grid of rows and columns, it allows users to sort information, do calculations, and make charts with ease. Today it is used worldwide.

Spreadsheets might have a reputation for being dull, but this story features space tourists, knitting, and crazy competitions.

Mike Koss, an American software developer who played a key role in Excel’s creation, shares his fascinating story with Gill Kearsley.

Eye-witness accounts brought to life by archive. Witness History is for those fascinated by the past. We take you to the events that have shaped our world through the eyes of the people who were there. For nine minutes every day, we take you back in time and all over the world, to examine wars, coups, scientific discoveries, cultural moments and much more. Recent episodes explore everything from the death of Adolf Hitler, the first spacewalk and the making of the movie Jaws, to celebrity tortoise Lonesome George, the Kobe earthquake and the invention of superglue. We look at the lives of some of the most famous leaders, artists, scientists and personalities in history, including: Eva Peron – Argentina’s Evita; President Ronald Reagan and his famous ‘tear down this wall’ speech; Thomas Keneally on why he wrote Schindler’s List; and Jacques Derrida, France’s ‘rock star’ philosopher. You can learn all about fascinating and surprising stories, such as the civil rights swimming protest; the disastrous D-Day rehearsal; and the death of one of the world’s oldest languages.

(Photo: Microsoft Excel logo. Credit: Thomas Trutschel/Photothek via Getty Images)