Foundation : An easy to use, powerful, and flexible framework for building prototypes and production code on any kind of device.
Electron : Build cross platform desktop apps with web technologies
lit : a ridiculously small responsive css framework
HTML EMAIL BOILERPLATE : This website and its sample code creates a template of sorts, absent of design or layout, that will help you avoid some of the major rendering problem...
This Is Responsive : Tips, Resources and Patterns for Responsive Web Design
A Responsive Email Framework from ZURB. Quickly create responsive HTML emails that work on any device & client. Even Outlook.