With all this talk of Agile, continuous delivery, Waterfall etc, it reminds me of a Software Engineering course I did at University. Specifically one of the methodologies mentioned which was a Spiral model. The gist was that instead of having one monolithic Waterfall process, you would still do the steps in waterfall, but you would release more often and have smaller releases. So that after a few iterations you would spiral in on the desired solution.

Upon reflection this seems like a proto-agile methodology, and because it doesn't have its own set of buzzwords and extra processes it seems like it could be a good reactionary (as a reaction against full Agile) methodology to use.