It's based on the google chrome rendering engine.
Looks a bit like the old "opera" before it got bizarre - the main vivaldi guy is an ex-main opera guy.
Has a sidebar with bookmarks, downloads, notes, history, which is nice. Firefox has only bookmarks. "Brave" browser has nothing.
On my "open 10 normal websites in tabs" test it uses about 15% more memory than firefox 57, and runs at about the same speed.
You can select two (or more) tabs and display them side-by-side (or above/under) at the same time.
There doesn't appear to be any way to move GUI elements around, like moving the navigation buttons ("back", "home", etc) except for putting the tab-bar on the bottom and re-ordering add-on icons. Firefox is much better in this regard.
Although they claim it's "customizable" it's really not customizable at all except thru hacks of a 13,000 line css file ("common.css") which doesn't have any useful comments. (I really hate "favicons" in tabs and changed about 20 entries in that file before they finally went away...by setting the size to zero). I wanted to make the GUI fonts larger and managed to do so for some parts of the GUI, but not the context menus (**). An update to the program erased my changes...
** If you start it with these intuitively-named flags (yes, that's sarcasm), you can "inspect element" of the GUI components:
Code: Select all
vivaldi --flag-switches-begin --debug-packed-apps --silent-debugger-extension-api --flag-switches-end