Active Job

Active Job backported to Rails 4.0 and 4.1

gem 'activejob_backport'

And create config/initializers/active_job.rb with:

ActiveJob::Base.queue_adapter = :inline # default queue adapter
# Adapters currently supported: :backburner, :delayed_job, :qu, :que, :queue_classic,
#                               :resque, :sidekiq, :sneakers, :sucker_punch

See how to use Active Job and the official repo