Firefox OS

Firefox OS was Mozilla’s attempt to build a mobile operating system from web technologies. I joined the team to design the initial proof-of-concept, then stayed on as Interaction Design lead for versions 1 and 2. I am particularly proud of the "uniquely web" user experience we  defined for version 2. Our objective was the to bring the seamless feel of browsing the web to a mobile OS. The results anticipated features that would become standard in later verisons of Android and iOS, including edge gestures and system-wide search.

Billboard for the Firefox OS 1.0 launch

Firefox OS 2.0: Gestures

Firefox OS 2.0: Camera app

Before Firefox OS became a real project, there was a proof-of-concept prototype, built hastily in advance of Mobile World Congress 2012 to show the world that a mobile operating system could be built on the web stack. I joined the effort to help create icons, and ended up designing the full interface. While very rushed (the home screen was slapped togther in one night in a hotel room in Paris) and dated, I think overall it holds up well.

Early Firefox OS prototype: Phone, Messages, and Camera

Early Firefox OS prototype: Lock screen, Settings, and Browser

Early Firefox OS prototype: Video player


  1. Gordon Brander and myself↩︎

Josh Carpenter

Josh Carpenter

I'm a user experience designer based in Vancouver, Canada. Most recently I led design teams at Google and Mozilla, working to bring virtual and augmented reality to the open web. My experience is a mix of product leadership, interaction design, visual design, motion graphics, programming and community engagement. A fox—not a hedgehog. Since 2019 I've been traveling and working on a series of personal projects, including an Electron-based Markdown editor and a deep dive into climate change.