Frontend

HTML5

resources

free

Frameworks

Bootstrap

Themes

https://startbootstrap.com/

Bootstrap 4 alfa

https://www.bootstrapzero.com/bootstrap-template/whats-new-in-bootstrap-4-theme

JavaScript languages

Angular 2

TypeScript

CoffeeScript

ES5

ES6

CSS

Sass

Less

http://learn.shayhowe.com/advanced-html-css/

paid

https://frontendmasters.com

https://www.coursera.org/courses?query=html%2C+css+and+javascript

https://www.codecademy.com/learn/make-a-website

https://www.codeschool.com/search?loc=hero&query=html