Firefox OS Simulator for Windows

This add-on is large (50-70MB), because it bundles a complete simulation of Firefox OS, including its default apps. So it takes multiple seconds for Firefox to install the add-on. Sometimes it takes so long that Firefox's Unresponsive Script dialog appears. If that happens, press the Continue button to let Firefox continue installing the add-on. It will eventually succeed.

See the 3.0 release announcement for info about new features and enhancements in the latest version. For more details, look at the GitHub comparison between 2.0.1 and 3.0 and the comparison between the versions of Gaia in those releases.

Unstable preview builds of the next version of the addon are available. If you're comfortable using incomplete software, and you're interested in seeing new features in development or are having trouble using the stable release, then try installing the latest preview build for Windows, Mac, and Linux.