Most people know nothing about "Waterfall Model" which if you think about it, is just commonsense meta framework using which you can implement any SDLC methodology. Pair it with "Spiral Model" (https://en.wikipedia.org/wiki/Spiral_model) and you are golden.

This excellent writeup by David Olson gives both the history and the correct understanding; The Myth of the 'Waterfall' SDLC - http://www.bawiki.com/wiki/Waterfall.html