The DuckDuckGo search engine is available as a Tor Hidden Service in the Tor network at:
Fortunately a plain HTML version of DDG is here:
but that means you can't install the search plugin with a simple click. However, click on the search bar menu arrow and you will see an extra menu option:
Add "DuckDuckGo (HTML)"
which will install a search bar plugin, but with a slightly confusing name.
To install, download:
and place it in your Firefox profile under
Firefox. You can then choose “DuckDuckGo Tor” in the search bar menu.
Last updated: <2014-09-11 23:26:47 CEST>