vxPlug 1.1 for Mac is available as a free download on our application library. This Mac app was originally designed by VertexDSP. VxPlug for Mac is included in Audio & Video Tools.
From the developer:
vxPlug can load plug-ins within a host application with the ability to: control plug-ins from a single user interface, and define the point where audio processing takes place in a flexible manner.
You may want to check out more software for Mac, such as Massive Audio Compressor, which might be similar to vxPlug.