Opera is built on Chromium project. Chromium is an open source project that uses WebKit, a free and open source rendering engine. WebKit is open sourced by Apple.
So, Google Chrome and Opera resemble a lot. They use process for each tab and look similar. The benefit of using processes to handle tabs is:
- Better security for browser as processes can’t circumvent security rules easily.
- Identification of inactivated tabs and swapping them out of memory, to keep browser light-weight.
To understand more about rendering and Chromium architecture, please visit the following: