WASHINGTON — Chinese telecom giant ZTE announced plans Monday to sell a low-cost smartphone using the open source Firefox operating system in the United States and Britain. ZTE said its Open Firefox OS phone will be sold through eBay in the US for $79.99 and 59.99 pounds in Britain. The phone, unlocked to allow use on a variety of mobile networks, uses the open source Firefox operating platform from the nonprofit Mozilla Foundation, which is aiming to break the dominance of Google's Android and Apple's iOS. "The global availability of the ZTE Open through eBay means that more consumers worldwide are now able, for the first time, to buy an affordable smartphone based entirely on open Web standards," the Chinese firm said in a statement. "The ZTE Open is powered by Firefox OS, which frees developers, operators and consumers from the constraints of existing closed ecosystems by using the Web as the platform for all functionality and applications." The statemen...