Metasearch v1.3.7
Metasearch is a meta-search engine in the form of an extension. It aggregates results from online search engines, that can either be general (such as DuckDuckGo) or domain-specific (such as IMDb).
All of these results are fetched through your browser (as separate tabs opened by the extension), so there is no centralized "Metasearch" service. This means that you are no more anonymous than if you were directly accessing these websites, but it also makes it very easy to access login-bound search engines such as library websites.
The Metasearch extension looks as much as an online search engine as possible, and is installed as one in the browser, so you can set it as the default search engine.