What cache, if any, do you good folks use?

Top of the night folks.

I am not referring to fna, ggc, akamai or Netflix (these are the ones I'm aware of), I'm talking about http, p2p and the likes.

People in the industry have told be about the following: Cache mara Extreme peering Blue coat

I myself have used bluecoat and cache flow (cacheflow turned into bluecoat). That too fifteen years ago

Apart from these, is anybody using anything else? What kind of saving are you seeing? Is your target saving or the accelerated performance some of these software/hardware provide?

Thanks