Facebook’s F8 developer conference was the social media giant’s most significant ever, outlining a broad strategy which will help it take on Google in far more applications, especially in the enterprise. However, moves to turn Messenger into a platform spanning business users to the internet of things (IoT), and even to open up WhatsApp, are also deeply worrying for mobile operators, whose own platform, RCS (Rich Communication Services) is ill-equipped to fend off the growing mobile power of the over-the-top messaging giants. Facebook has made a number of steps in recent years to open up its key assets to third party developers and build up an ecosystem that takes it well beyond social media. The goal has been to make…