Developers in distress...The next release of the Palm operating system will ship in multiple versions for different hardware platforms, which could leave developers facing a nightmare of compatibility problems. As customers demand a greater variety of handhelds with faster and more powerful processors, PalmSource, the recently separated software business of Palm, has decided to release different builds of its operating system (OS) to support each one. Michael Mace, chief competitive officer at PalmSource, told silicon.com: "PalmSource has a different business model than some other OS companies. We've made the OS a lot more customisable by partners and licensees, so there's room for a lot of optimisation." He said: "There are already effectively different OS versions for different licensees. In particular, Palm OS 5 has a 'hardware adaptation layer' which customises the OS to a particular chip." Geoffrey Baird, CEO at mobile application developers Commtag, said: "Palm is definitely risking compatibility problems by going for a multi-processor strategy. PalmSource's Mace said that Palm developers need not fear compatibility issues. He said: "Different versions of the OS have to pass a big suite of compatibility tests. The idea is to allow innovation under the hood without breaking app compatibility." But Baird said: "Even if they say that 80 per cent of applications work, the 20 per cent that don't tend to be the most useful. The more useful an application is, the more you have to customise it." Microsoft has faced the same set of problems, but it chose the opposite course - it has stuck to a single version of its PocketPC 2002 operating system, even though it doesn't make the best use of many of the features of the latest generation of processors. Customers have been disappointed with the first generation of devices powered by Intel's new Xscale chips - user benchmarks on PocketPCs powered by the 400MHz Xscale chip have in some cases been slower than the old 206MHz StrongARM chips. Mace told silicon.com he is confident future Palms will work well with Xscale. He said: "Intel is a member of our Palm OS Ready program, and we've been working with them to ensure that good HAL software will be available for use with XScale." Said Mace: "No OS ever takes advantage of every feature of a chip, but we believe that Palm OS 5 systems running on XScale will take significant advantage of it. To know more, we'll have to wait for those systems to ship." In effect, PalmSource will have to balance three things - making an operating system that runs efficiently on a wide variety of chips, while taking care not to make life too difficult for its developers. Many of those developers will already be upset by the fact that many applications written for previous versions of PalmOS weren't compatible with OS5. Worse still, having taken since 1999 to bring OS 5 to market, PalmSource will also have to work hard to get the next version out in reasonable time, before Microsoft eats too much of its market share.