Firefox OS is an open source mobile operating system that uses web technologies. It targets emerging markets with affordable hardware that does not require a credit card. It has multiple hardware and mobile partners. Firefox OS uses a streamlined software stack and allows apps through three levels of access - hosted, privileged, and certified. It has many web APIs to provide capabilities and is defined by a manifest file. The Firefox Marketplace hosts apps and there are developer tools and references provided. Firefox OS is launching in European and Latin American markets through mobile partners. It provides a low-cost alternative that can be reused across platforms and allows various monetization models for developers.