Bootstrap is one of the most popular modern front-end web development framework. It’s full feature-packed with many component and js liabraries,validation and other things which you may need to design your interface.
It has a 12-grid responsive layout, It already contains 13 custom jQuery plugins for common UIs like carousels and modal windows, a Bootstrap customizer, and more.
Bootstrap is well-documented and many tutorials and demo are available on the site too.
Check the links to see the demo
Foundation is also a popular responsive front-end framework With his modern HTML5 framework, You can define a big screen size web interface to mobile layout base web UI using it.
It has rapid-prototyping capabilities, a responsive grid system and much more.
It has may feature to modify it as per your needs with Typography, Callouts & prompts, Content and all.
A dead simple, responsive boilerplate and one of my favoraite. It’s a responsive framework which has all the possibility to make a Cool and effective responsive web layout without any extenal liabraries.
It is very lite and allow to customise itself as per design needs.
Training and demo links