In approximately this order: 1. Trust and privacy issues (limited phoning home, separate search/address bars, etc. plus generally promoting a more open Web) 2

In approximately this order: 1. Trust and privacy issues (limited phoning home, separate search/address bars, etc. plus generally promoting a more open Web) 2. Stability and reliability (in the sense that things continue to work over time) 3. Gets updates (but doesn't force them unexpectedly) 4. Large and flexible add-ons ecosystem (and I'm already familiar with it) 5. Momentum/habit In practice, 1-3 rule out Chrome as my everyday browser choice, while 1 and 3 rule out IE, so today Firefox basically wins by default on my Windows 7 PCs. If Mozilla rearranges or breaks too many things and if it's then no longer possible to have a secure version of Firefox without getting those other changes, most of the above points will become deal-breakers for Firefox as well. In that event, I'll mostly likely switch to something like Pale Moon for my own use and just keep the big names around for testing.