Bootstrap : Build responsive, mobile-first projects on the web with the world's most popular front-end component library.
Bootstrap is an open source toolkit for ...
Email-Blueprints : Email Blueprints is a collection of HTML email templates that can serve as a solid foundation and starting point for the design of emails.
Kickstrap : Twitter's Bootstrap with themes, apps, and other enhancements
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...
YAML : A modular CSS framework for truly flexible, accessible and responsive websites
A free and modern UI toolkit for web makers based on the popular Bootstrap 4 framework.