Naive LPF is a resonant low-pass filter with envelope follower. This filter has been developed to closely model the way some real world analog circuits work, as opposed to some other techniques which, while well adapted to the math processing power of a computer, just don't seem to render the same organic feel.
Not to say that those techniques aren't just as valid, but I was going for a vintage, analog feel on this one. I'm primarily using this project as a test-bed for a full soft-synth, and in that realm we typically want "colorful" filters to make "warm" sounds.
This was not intended to be a "clean" or "transparent" filter by any means! It is my first attempt at an audio filter, my first VST plugin, and my own first guess at how to approach a low-pass filter -- hence the name "Naive LPF". But really at this point it should be called the "Not-So-Naive LPF", because it's actually a quite sophisticated implementation and it's turning out to be useful. I'm finding it really does capture some of that vintage warmth I'm always looking for.