Fluid and liquid not only layout but typography, images, sliders etc.
This would be suitable for clients from hell
Well, it’s cheap way forward. For those who want to provide more convenience to their “mobile visitors” and cannot maintain couple of site versions (desktop, mobile, smartphone, tablet, etc.)
I strongly disagree with the word “cheap”. Removing duplication of code is not cheap, it’s good development practice. Supporting multiple devices on one implementation is not cheap, it’s the right thing to do. Delivering the same content to users on mobile as well as desktop is not cheap, it’s good user experience.
adaptive is the way forward, browsers don’t need to “respond” when users move their browsers, simple fix use device-width in media queries rather than min/max-width
I think you’re using adaptive in a different way than I would – which often happens with terminology referring to new technologies.
For me, responsive is just one type of adaptive. Progressive enhancement is another. We’ve been doing adaptive for years, but responsive is a new approach to dealing with viewport size in particular.