This is an extremely experimental, extremely unofficial project to enable browsing .onion sites and clearnet sites via Tor in regular Firefox. The strongest privacy protection for this activity is still Tor Browser and will be for a long time. To get Tor Browser, go here:
The purpose of this extension is to experiment with side-by-side integration of Tor and I2P in mainline Firefox and potentially, a hardened Firefox distribution.
This is a meager prototype, it lacks functionality and shouldn't be used under any circumstances to protect your anonymity at this time. If and or when that becomes an option, the contexts in which that is true will be made clear.
This plugin's viability is directly related to the viability of Mozilla and Tor's work on hardening Firefox itself and of particular interest are the "Uplift" and "Fusion(Firefox Using Onions)" projects.
Project uplift seems to have largely been accomplished?