Schedule::Cron is a Perl module that provides a simple but complete cron-like scheduler. It can be used for periodically executing Perl subroutines. The philosophy behind Schedule::Cron is to call subroutines periodically from within one single Perl program instead of letting cron trigger several (possibly different) Perl scripts. Everything under one roof. Furthermore, Schedule::Cron provides a mechanism to create crontab entries dynamically, which isn't that easy with cron. It knows about all extensions (at least all extensions the author is aware of, i.e those of "Vixie" cron) for crontab entries like ranges including 'steps', specification of month and days of the week by name, or coexistence of lists and ranges in the same field. It even supports a bit more (like lists and ranges with symbolic names). It has existed since 1999 on CPAN and is successfully used in many projects.
Jmx4Perl provides an alternate way of accessing Java JEE Server management interfaces that are based on JMX (Java Management Extensions). It is an agent-based approach where a small Web application deployed on the application server provides HTTP/JSON-based access to JMX MBeans registered within the application server. It is set up from a handful of Perl modules, which can be integrated seamlessly in your own programs. It also includes a Nagios plugin, check_jmx4perl, a jmx4perl command line tool for remote JMX queries and operations, and a readline-based JMX shell j4psh, with context sensitive command completion and syntax highlighting.