Rated 5 out of 5 stars
Rating this anything but the full five stars would be sacrilege. Let me tell you why:
my primary browser was Opera for a long time. It came with a full feature set for custom search engines and I was happy to use it for years. In dire need for a new browser (Firefox) and a replacement for the custom search feature, I found my salvation in InstantFox.
It does exactly what I want and is configurable enough, that other search providers work with suggestions.