Ruby

Passenger 5.1: a new milestone in robustness, security and efficiency и Is Ruby dead? Hell no! — Analyzing RubyGems stats for 2016
Ruby’s Mysterious Triple Equals Operator, a.k.a. Case Equality Operator, Bundler and Gemfile best practices и Auto-reconnect for ActiveRecord connections
Writing a Sprockets plugin, KaTeX for Ruby и Chartkick: data visualization made easy with Ruby

JavaScript

Fabric is Joining Google, RethinkDB: why we failed, Learning JavaScript in 2017 sucks and this is awesome! и Webpack 2.2: The Final Release
3 New CSS Features to Learn in 2017, How to Create Spotify Colorizer Effects With CSS Blend Modes и removeEventListener and this
Mermaid — generation of diagrams and flowcharts from text in a similar manner as markdown, LocalForage — a JavaScript library that improves the offline experience of your web app by using an asynchronous data store with a simple и Tone.js — a framework for creating interactive music in the browser