A new skirmish of tech titans is taking shape as Apple Inc. and Microsoft Corp. reignite a battle that dates back to the formative days of the personal computer age.The companies’ co-founders, Apple’s Steve Jobs and Bill Gates at Microsoft battled early in their history before largely burying the hatchet. In recent months, both companies have taken up arms again in a skirmish that is rolling over tech companies and their clients.Apple, in its legal battle with Epic Games Inc., accused Microsoft of being the puppet master behind the game maker’s case. Epic Games has accused the iPhone maker of anti-competitive practices, while Microsoft has accused Apple of restricting its ability to reach users with its own videogame service.On Thursday, Microsoft Chief Executive Officer Satya Nadella initiated Windows 11 with what was broadly seen as a swipe at Apple and the controls it displays over its iPhone App store, but without mentioning the rival directly. Both companies are positioning themselves for an approaching fight over the augmented and virtual reality market that is seen as the next main frontier in computing.