When Bill Gates and Paul Allen founded the company they called Micro-Soft 50 years ago this week, it was to sell a version of the Basic computer language for the Altair, the first proto-PC.

Their first product set the pattern for what was to follow. Microsoft’’s fortunes soared, stagnated and soared again with the tech industry’s periodic platform shifts. But the heart of its business always lay in providing developers with tools to build their applications and platforms to run them on.

With a globe-spanning fleet of data centres under its control, Gates and Allen’s company has come a long way from the Altair. Thanks to a well-placed early bet on generative AI, it enjoyed a notable boom as its mid-century loomed. But the outcomes of platform shifts in the tech industry are not always predictable, and it is still too soon to tell if Microsoft has seen off the potential threats from this one.