Apple really needs to update Safari to let people choose their search engine, instead of just having the list of blessed search engines to choose from.
This is what I used, but it’s a bit of a hack. It has to hijack one of the other search engine, which then becomes unusable. It also doesn’t show the search term in the address bar, like the person was asking for.
Apple really needs to update Safari to let people choose their search engine, instead of just having the list of blessed search engines to choose from.