Faktory is a language-agnostic, persistent background job system.
Cadence is a distributed, scalable, durable, and highly available orchestration engine we developed at Uber Engineering to execute asynchronous long-running business logic in a scalable and resilient way.
Celery is an asynchronous task queue/job queue based on distributed message passing. It is focused on real-time operation, but supports scheduling as well.
Fireworq is a lightweight, high-performance, language-independent job queue system.