Rack is the gem that provides the interface between web frameworks (ruby on rails, sinatra) and web servers (webrick, puma, unicorn) in ruby world.

Rake is a Make-like task runner in Ruby. First define a list of tasks in ruby syntax in a Rakefile and then invoke the task with rake command.

Bundler is for dependency management in ruby projects.

A ruby gem is a software package that contains a reusable ruby application or library.

rbenv is for managing multiple Ruby versions and here are some of its commonly used commands summarized for quick reference.

JavaScript typeof returns and falsy values.

How to dynamically insert js.

How to quickly generate random secure token with nodejs

How to generate 26 english letters in js.

How to view memcached data.