odd-jobs (hackage): Background jobs library for Haskell.  Extracted from production code at Vacation Labs.  Inspired by the Delayed Jobs library in Rails.  Queue backend is a Postgres table.  Queue is monitored using, both, LISTEN/NOTIFY and polling the DB.  Comes with an in-built admin UI.  Comes with utilities to help you built a CLI for your job-queue.  Highly configurable and monitorable
Keywords: bsd3|library|program|web