Ruby

Use An Ask, Don’t Tell Policy With Ruby и Patching Rails Performance
Benchmarking exceptions in Ruby — yep, they’re slow и From Ruby to Erlang. Beginner’s Mistakes
Do You Know The Gem Gem? и Better Commit Messages with a .gitmessage Template
What’s does quality software mean?, Inch — a documentation measurement tool for Ruby и Rstreamor — stream your data using HTTP/1.1 range requests and partial responses

JavaScript

io.js 3.0.0, Stop pushing the web forward и On PPK’s moratorium on new browser features
TypeScript vs Haxe, Which is the Better Compile-to-JS Language? и The JavaScript Looping Evolution
7 tips to publish your React components, New React Devtools Beta, React.parts — a catalog of React components и PostCSS.parts — a searchable catalog of PostCSS plugins
Butler.js is the voice driven, portable butler for your personal needs, Minigrid — minimal 2kb zero dependency cascading grid layout, OS.js — JavaScript Web/Cloud Desktop Platform и 10 Free JavaScript Books