Opera is one of the oldest third-party web browsers for Windows and other platforms. Opera existed even before the days of Firefox and Chrome. But Opera’s old web rendering engine called Presto was getting sluggish and lacked some of the features offered by competitors like Chrome. So they switched to Chrome’s web rendering engine Blink and Opera’s new avatar became as fast as Chrome itself. But in this update frenzy, Opera also dropped many of the classic elements that it was known for and adopted the newer user interface.
Now another open-source web browser called Otter has taken upon itself to make the best of both worlds and mix the newer web rendering engine from modern Opera and classic user interface from the Opera 12 (classic Opera). Otter is using Blink engine (same as Google Chrome browser) and therefore is blazing fast. On top of that, it is using a classic user interface making it even much faster than Opera or Vivaldi (another web browser that takes inspiration from the glorious past of the classic Opera).
I would not recommend using Otter for everyday serious work, but for casual web browsing, Otter seems to have everything including an in-built blocker for trackers containing a large number of databases. In the forthcoming versions, Otter will only improve both on the features offered, the stability and the performance.
You can download Otter web browser from https://otter-browser.org/.