I think that came during the period of Black & White by Lionhead Studios. (which was a milestone in using gestures to cast spells by swirly your mouse around)
And Opera openly admitted that they copied B&W there, because they considered it a very useful feature. It even came in a sub-version, which at that time was somewhat unusual for such an important feature.
> right click drag left to go back, right click... swirl? to reload
I still customise my Chrome and Firefox mouse gestures add-ons to work exactly this way, despite having long forgotten where those conventions originally came from.
I was an avid Opera user around 2004. True MDI interface, mouse gestures...come to think of it, that was the peak of my web browsing.
Sure, my current browser supports the latest web standards that enable great things and sure, my internet speed is a lot higher. But just from a "browsing the web" perspective, Opera was the high point.
No, it was not. That's a popular myth, but it's wrong. There were other browser with Tabs before opera event tried them. And Operas first attempts wasn't really Tabs in the modern sense. It was just a poor working button-bar for an MDI, which was a bit cumbersome to use. They fixed it two versions later, around the time when the feature gained attention in other browsers and even Mozilla Suit got it's first Extension that became so insanly popular that it was build into Phoenix (later renamend to Firebird, then Firefox) out of the box.
Though, Opera tried many things in that area. There never really lost the MDI-Spirit and went with different approached than most other TDI-Implementations. Made it more useful for some, more complicated for others. So for certain specific functions they probablly were the first ones.
However, Opera supported an MDI interface before it supported tabs, and if you count that it may have supported multiple browser windows within one MDI window even earlier, which could be said to be a form of tabs.
Everything depends on how you define "tabs", as usual.
And in a HN thread a couple weeks ago someone posted about how “everyone” switched to Chrome because it invented tabs, if you want to know what today’s web developers think.
I loved tabs in Galeon, it's the only browser I remembering having it at the time, but I probably didn't try Opera. I was sad when Galeon went away (or removed tabs? I don't recall) and I couldn't find another browser with tab support for a while. Again, I may have overlooked Opera :)
Galeon was also the only usable Linux browser having a native look on Gnome (Epiphany was the other one, but I remember it having more difficulty with a lot of sites).
It embedded the Mozilla engine (which was a supported use case back then, before Firefox) but launched a lot faster. Usable on a 200Mhz machine at least.
