ReaFir
ReaFir is a multi purpose plug featuring five different modes – EQ, Gate, Compressor, Convolve L/R and Subtract.
Kind: concept (effect-summary) Source: REAPER Effects Summary Guide v3.04

ReaFir is a multi purpose plug featuring five different modes – EQ, Gate, Compressor, Convolve L/R and Subtract. Each of these functions is entirely independent of the other. If you wish to use more than one of its functions (for example, compressor and EQ), then you need to use a separate instance of ReaFir for each function. Each mode has its own specific controls: in addition there are some parameters that are common to the different modes. The information that follows has been adapted from the REAPER Wiki.