Firefox vs. Opera: Which is the better browser for you?
Desktop Web Browser Speed Test: Chrome 17 vs Firefox 10 vs IE9 vs Opera 11 | Redmond Pie
Opera Skin For Firefox - gHacks Tech News
Maxthon 3 Surpasses Safari on European Economic Council Browser Ballot: Joins Opera, Google Chrome, Firefox and Microsoft Internet Explorer on the First Page - Maxthon Browsers Blog
Get an Opera-Style Panels Sidebar in Firefox
Opera vs Firefox: Two Smaller Browsers Duke It Out in 2022
Firefox vs Opera for Android: Which Is a Better Alternative to Google Chrome
Is it possible to get a sidebar in Firefox similar to Opera GX? : r/firefox
Chrome, Edge, Firefox, Opera, or Safari: Which Browser Is Best? | PCMag
Vinnytsia, Ukraine - April 21, 2021: Set of popular logo internet browsers. Google Chrome, Mozilla Firefox, Opera, Safari, Microsoft Edge, UC Browser Stock Vector Image & Art - Alamy
Opera vs Firefox: Features and performance comparison
Opera Browser vs. Mozilla Firefox: Which is Better Choice?