From FabFilter Software Instruments:
FabFilter Pro-Q gets you the possible sound quality and a gorgeous interface. FabFilter Pro-Q is designed to help you achieve your sound in the quickest way. Via the large interactive EQ display, you can create bands where you need them and select and edit multiple bands at once. Pro-Q offers top quality linear phase operation in addition to zero latency modes, Mid/Side processing, variable stereo placement of EQ bands, and an intelligent solo feature and a built-in spectrum analyzer. Features include operates either in zero latency mode or in linear phase mode with adjustable latency, each band can operate on the stereo signals or on the left or right channels independently for per-channel EQ-ing, multi-band selection and editing for maximum ease and efficiency, MIDI learn, stereo and mono plug-ins available, Smart Parameter Interpolation, and supports common Pro Tools hardware control surfaces.