Apple and Microsoft to push rival visions Apple and Microsoft will be exhorting developers to support their rival visions of computing with more urgency than usual at sold-out conferences on opposite coasts of the US starting on Monday. Apple is providing final details at its annual Worldwide Developer Conference in San Francisco on its summer release of Mountain Lion - the next iteration of its operating system for Mac computers, while lifting the lid on the new iOS 6, the interface and apps for the iPhone and iPad. Microsoft's TechEd in Orlando, Florida will evangelise Windows 8 - the forthcoming dual operating system for PCs and tablets that uses the same style of tiled interface already introduced on Windows smartphones and Xbox 360 games consoles. But they face completely different problems in trying to galvanise developers to support their software ecosystems - Apple's App Store is suffering from a surfeit of apps, with downloads falling and user attention waning, while Microsoft must persuade developers to produce apps for tablets that have yet to record any sales. "There isn't an installed base of users for Windows 8 and developers want that more than anything else in order to sell their applications," says Van Baker, an analyst with the Gartner research firm. He is among the many doubters that Microsoft has got it right with Windows 8, which ambitiously has two different interfaces - a regular Windows desktop hidden behind the "Metro" tiled interface optimised for touchscreens, which was first seen on Windows smartphones. "It feels like two very different environments stuck together in an unnatural fashion," he says. Tim Cook, Apple chief executive, has described efforts to create hybrid laptop-tablet combinations that can take full advantage of Windows 8 as being as unsatisfactory as combining a toaster with a refrigerator. Apple has insisted on maintaining two different operating systems, one for mouse-based Macs and one for touchscreen devices, although Mountain Lion is inspired by the iPad's interface, with items such as a messages app, notifications feature and game centre moving over to the Mac. Apple App Store daily downloads of the top 200 free apps continued to fall in April - down 5 per cent month-on-month to 4.23m, according to the Fiksu app ranking company. They had fallen 30 per cent in March to 4.45m. The cost for brands to acquire a loyal user rose 12 per cent in April to $1.45 and analysts are talking about a "throwaway mentality" emerging as 65 per cent of consumers stop using a downloaded app within 30 days. Nevertheless, with more than 600,000 apps, including about 200,000 for the iPad, Apple retains a big lead over competitors and its annual developer events tend to galvanise its community. Other rumoured announcements that would create excitement include a new non-Google map app, improvements to and wider availability of Siri voice recognition software, Facebook integration, the opening up of Apple TV to app developers and a new line of MacBooks with higher resolution screens.