...It’s an echo of the so-called browser wars of the 1990s, when Internet Explorer and Netscape Navigator fought for dominance on the personal computer. This time, though, the struggle is shaping up to be over which company will control the mobile world — with browsers on smartphones and tablets. Entrenched businesses are at stake. Google’s browser-based business apps, for instance, threaten Microsoft’s desktop software, and mobile Web apps threaten Apple’s App Store.