SVG masks. This is a very interesting technology. It allows us to create a lot of cool effects, even in IE. I created an example for one of my answers on toster.ru. It looks nice and it has been picked on CodePen recently, so I think I should share it here too.
Simple UI framework. RSCSS, REM-based sizes, fluid typography and other nice ideas. This website is powered by it.
Boilerplate for static promotional websites. Pug, LESS, PostCSS, ES6+, Gulp, Webpack, BrowserSync, ESLint, Stylelint, auto-generated docs...
Library for creating galleries of photos with effects based on WebGL shaders.