With the announcement that Microsoft is to launch its own iPad-killing tablet, the tech world is thrilled at the prospect of a rekindled war between old enemies. Apple versus Microsoft is the classic tech battle. Microsoft is Apple’s Moriarty. The two tech giants are almost mirror images of themselves – Microsoft forever the evil copyist, Apple the plucky innovator.

In the beginning Apple and Microsoft were bosom buddies. Bill Gates was pretty enamoured of the Mac: “To create a new standard, it takes something that’s not just a little bit different. It takes something that’s really new and really captures people’s imagination and the Mac, of all the machines I’ve ever seen, is the only one that meets that standard.”

Microsoft was recruited as the first third-party applications software developer for the Mac. But even then Steve Jobs was worried that it might try to copy the Mac team’s ideas into a PC-based user interface. And in 1983, Microsoft duly announced a mousebased system graphical user interface called Windows. Jobs went ballistic.

“Get Gates down here immediately”, Jobs fumed to Mike Boich, Mac’s original evangelist who was in charge of relationships with third-party developers. “He needs to explain this, and it better be good. I want him in this room by tomorrow afternoon, or else!”

Bill Gates duly showed up the next day to get an earful from Steve: “You’re ripping us off! I trusted you, and now you’re stealing from us!”

Bill just stood there coolly, looking Steve directly in the eye, before squeaking up: “Well, Steve, I think it’s more like we both had this rich neighbour named Xerox and I broke into his house to steal the TV set and found out that you’d already stolen it.”

The line had been crossed, and Apple and Microsoft were now at war, with Apple raising objections to Windows 1.0 in 1985. Negotiations led to a partial agreement, where Apple licensed some Mac code for Windows 1.0. This would prove a massive mistake. When more Mac-like features were added into Windows 2.0 Apple sued in March 1988, looking for $5.5bn in compensation.

Apple listed 189 GUI elements as copied – all but 10 of which the court decided in 1989 had been licensed to Microsoft in that fateful Windows 1.0 agreement. In 1992, the judge tossed out the 10 remaining disputed elements, effectively ending the long-running case.

Apple could have done with Bill’s billions by this time, and the company was on its knees – resulting in the return of Steve Jobs in 1997. Jobs swallowed his not-inconsiderable pride and wrapped the whole thing up that year, with Apple and Microsoft signing a patent cross-licensing agreement in return for Microsoft publicly being nice to it. Microsoft even invested $150m in the struggling Apple.

Gates appeared on a giant video screen behind Jobs during his 1997 Boston Macworld Expo keynote, when Steve announced the pact. The crowd of Mac faithful booed. Jobs hushed them for their “childish behaviour” despite his own years of equally puerile Microsoft bashing.

It was Apple’s lowest moment in its fight with Microsoft, but also the springboard for its monumental turnaround – culminating in its passing Microsoft to become the world’s most valuable tech company in May 2010.

The two leaders had little nice to say about each other for most of their lives.

“The only problem with Microsoft is they have absolutely no taste,” sneered Jobs. “I am saddened, not by Microsoft’s success. I have a problem with the fact that they just make really third-rate products.”

Shortly before his return to Apple, Jobs conceded defeat to Microsoft in the Mac versus PC battle: “The desktop computer industry is dead. Microsoft dominates with very little innovation. If I were running Apple, I would milk the Mac for all it’s worth – and get busy on the next great thing. The PC wars are over. Done. Microsoft won a long time ago.”

Gates couldn’t even work out why Jobs would want to go back to Apple: “I can’t figure out why he is even trying. He knows he can’t win.”

But win he and Apple did. Microsoft’s not a beaten wreck, but its new Surface tablet is starting a long way back from the iPad. Despite pioneering the idea of tablets as far back as 1991 with its Windows for Pen Computing and 2002 XP Tablet PC Edition, Microsoft has a big battle on its hands to overturn the all-conquering iPad.

We must celebrate possible new hostilities between these old foes, even if just to keep Apple on its toes and innovating like it does best.