Spotlight’s search window provides ‘AsYouTypeTopHit’ ranked search, including a measure of recency, 3 opaque scores, related search, and hits across multiple search domains. Here’s how it does that.
Biome
It has its own folder in ~/Library, and no less than 7 of its own Private Frameworks. But what is it, and what does it do? This is as much as I know about it.
The Eclectic Light Company 