[Natanael_L]

Vivaldi seems neat, which is essentially Chromium with a HTML5 GUI built by the old Opera folks intended to restore the best features of old Opera, with a heavy focus on customization.

My hope is that Mozilla will take the direction of using Servo to build something Vivaldi-like (instead of everybody running with Webkit/Blink) and start to restore old API:s and frameworks from old XUL-Firefox that all the best old addons relied on (things llike NoScript, Session Manager, Vimperator, uBlock, Tab Mix Plus, etc...) instead of just sticking with a blackbox rendering engine and settling with Chrome addon API parity.

[cm3]

Have you tried using Vivaldi? It's awfully slow to respond to user interaction because it's all HTML. Say what you want about XUL, but for something aiming to be like HTML it never felt slow. If Vivaldi's non-existing responsiveness is what the new Firefox will be, then they should seriously consider to rewrite the whole thing like a game (in OpenGL/Vulkan) instead. Oh and XUL was optimized for memory efficiency, which will have to be reoptimized for the HTML-only interface, but that can benefit the whole web.

[angry-hacker]

Vivaldi is much faster than Firefox on both Linux and Windows, where I'm using it. Of course it's still alpha software, but the UI is blazing fast compared to FF.

[cm3]

It's substantially slower than Chromium and Firefox for me on Linux. Both Chromium and Firefox are very fast in comparison on my machines. I'm glad it's faster for you, I really am.

[lsh]

I do believe Otter is doing a better job of restoring Opera's past glory, feature-wise. Vivaldi, even with it's HTML gui feels like another opera/chrome/chromium derivative.

Plug: http://otter-browser.org/

[rplnt]

They still suffer from the "different" rendering engine. Some things, it seems, can't be achieved beyond that.

[X-Istence]

Qt5 ships with WebKit.