Opera web browser is developed by Opera Software. It was initially released on April 1995. It supports the major operating systems: Windows, macOS, and Linux operating systems. According to W3Shools.com, Opera is the 5th most used browser based on it's usage statistics as of June 2017.
Version of the Opera browser installed on your system can be checked in a few easy steps:
opera://about
in the address bar and hit enter.