Want to use some of the comprehensive FX plug-ins that REAPER provides, but stuck in another host? Haven't made the switch yet? Fear not -- you can download ReaPlugs, a package of FX that includes many of the plug-ins that come with REAPER, for free!

General features of ReaPlugs:
Support for Windows 98/ME/2K/XP/Vista/W7, WINE
Fast, usable UIs with good metering
Low CPU and RAM use
Highly configurable
No copy protection
Portable (copy installed files and run)
Freely usable

ReaFIR Multi FX Plugin by Cockos

ReaFIR features:

FFT based dynamics processor (requires host plug-in delay compensation).
Supports FFT sizes of 128-32768.
Useful in/out frequency response display.
Supports defining response curves both using any number of points, or freehand mouse.
EQ - can be used as a linear phase mastering EQ, or as a super-effective surgical EQ.
Compressor - can compress at a fixed ratio with a per-band threshold.
Gate - can gate with per-band threshold.
Subtract - can build noise profiles and subtract noise from the signal.
ReaFIR is part of the free ReaPlugs VST FX Suite.