UnsharpMask

Works very much like the Photoshop version. Stems from the old days when it was an optical / printing process. A slightly out of focus print of your negative was exposed onto transparency film, this was then sandwiched with the negative and exposure onto light sensitive paper. Two controls are 'sharpness' and 'balance'. Sharpness controls the multiplication factor of the blurred version and the original version before the later is subtracted from the former. Balance controls the blur amount.

Slightly more pleasing to the eye than Nuke's standard sharpening node.