The mark3 is a free, PC only mid/side limiter with mono to stereo and widening capabilities.
The Audio Classic Serie is a bundle of Kjaerhus 9 Classic Serie mixing and mastering audio plugins. Including the classic auto-filter, chorus, compressor, delay, EQ, flanger, limiter, phaser and reverb. The classic serie goal is to emulate the warm and rich sound of vintage high end analog gear from the 70’s and 80’s eras. Kjaerhus unique “Warmth & Saturation” algorithms will give your sound a sweet and lively analog color. And it’s totally free !
This one may not look like much but comes pretty close to Waves’ limiter plugin and it’s free .