To kill a panel, use Ctrl + key x

A quick overview of new JavaScript features in ES2015, ES2016, ES2017 and beyond.

Learn by example: cssreference.io is a free visual guide to CSS. It features the most popular properties, and explains them with illustrated and animated examples.

This document is a collection of Unix/Linux/BSD commands and tasks which are useful for IT work or for advanced users. This is a practical guide with concise explanations, however the reader is supposed to know what s/he is doing.

Un aide mémoire

A very useful list off all the Emacs functions and variables accessible from the web or you mobile. It is also possible to access to this from Emacs itself by invoking describe-function or describe-variable.