Motorola, NEC, NTT DoCoMo, Panasonic Mobile Communications, Samsung Electronics, and Vodafone have a lot of ground to make up. About 15.1 million smart phones and pocket PCs run Windows and 106 million run Symbian, research firm iSuppli says. Only 12.6 million use Linux. Still, wider use of the open source code could attract a new set of developers, which should benefit customers and equipment makers.