Linux is gaining credibility and functionality as a mobile operating system, but its greatest challenge remains the risk of fragmentation, with a host of different distributions and industry groups all vying to drive the platform. One of the most important is the LiMo foundation, set up in mid-2006 and spearheaded by Motorola, and this is now looking set to be the dominant force in mobile Linux unification, to the benefit of the US handset maker. Last week it gained two significant new supporters, MontaVista ‘ the most successful of the mobile open source OS providers to date ‘ and Broadcom, which is building up momentum at last behind its assault on the 3G handset baseband sector, and is making an…