Here are some frameworks that give you a solid foundation when creating websites and aren’t packed full with features.
Girder is a minimalistic grid toolkit that builds flexible layouts divided into logical sections. Its built with Sass. It can scale based on your project’s needs as it includes support for complex media queries using the Breakpoint() compass plugin.
Cardinal is a small mobile first CSS framework with its focus primarily on responsive web applications. The purpose of Cardinal is to ‘make it easier to rapidly prototype, build, scale, and maintain CSS’ for responsive web apps. It does omits many aesthetic design decisions that will often drag down larger, more complicated CSS frameworks, leaving the design to you.
Typeplate is a typographic starter kit that doesn’t make aesthetic design choices, but defines proper markup with extensible styling for common typographic patterns.
Gridism is a simple CSS grid that comes with in-built patterns for responsive design.
The flat styled Furatto is a front-end framework for rapid web development based on other frameworks, such as Twitter Bootstrap, Foundation…, as a start point.
PocketGrid is a lightweight (0.5kB) pure CSS responsive grid system that allows for an unlimited number of columns and breakpoints. Instead of creating grids with rows and columns, PocketGrid has a more flexible system with blocks and block groups. Block groups are similar to rows, and blocks are similar to columns, allowing for more flexibility than traditional grids.
Designed for rapid prototyping (but also runs well in production environments), .Fitgrd is a solid foundation for designers that don’t want to have their pages look like they are “bootstraped”. The grid is divided into twelve columns with percentual widths, with each column having a two percent margin on both sides.
Kraken is a lightweight, mobile-first boilerplate that includes just the essentials: A CSS reset to ensure cross-browser compatibility; A responsive, mobile-first grid; A well-designed, fluid typographic scale; CSS3 buttons; Basic form styling; Optional add-ons for more functionality.
Markup is a simple collection of layouts, widgets, UI styles and other components that you can make use of in your projects in order to code rapidly and efficiently.
Topcoat is a fully themable and open source CSS framework to help you work with and create web apps with ease.
Cascade Framework operates by splitting your CSS into seperate files based on features rather than selectors and by implementing a modifier design pattern inspired by SMACCS and OOCSS.
Responsable is a responsive grid system based on Semantic.gs and powered by LESS.
Clank is an open source prototyping framework that helps you work with mobile apps.
Responsive Web CSS
Responsive Web CSS helps you layout your web pages within minutes. You can specify target devices and resolutions for responsiveness, and then easily download the site skeleton.