TimeMachine is an open source Java scheduler that can run high volume of jobs with many different type of 
schedules. It supports repeating schedule on fixed interval, CRON based expression, or even custom 
schedules. The scheduler can manage job executions with thread pools, and it can persist job data into 
different storage. Users may run the scheduler as stand-alone server, or deploy as web application. The 
scheduler engine is using a stack-based service container that is easy to configure and extend by developers.

Main Features:

* A stand-alone scheduler server with simple Properties configuration file.
* A web application (war) to run and manage the scheduler.
* Support job implementation in either Java or scripting language (Eg: Groovy)
* Support multiple thread pools for isolated jobs execution.
* Support in-memory or database data store.
* Support scheduler clustering - multiple scheduler nodes with single logical scheduler.
* Support job history recording.
* Built-in JobTask: LoggerJobTask, ScriptingJobTask and OsCommandJobTask.
* Built-in Schedule: RepeatSchedule, CronSchedule and DateListSchedule.
* Built-in Service: Crontab that's similar to Linux/Unix OS crontab service.
* Built-in Service: JobLoader to load any job and schedule with simple properties file.

See documentations on