NTPmon is a Web-based monitor for (usually LAN-based) NTP servers. It provides a small number of health metrics that help to locate NTP configuration or operational trouble spots. It uses RRDtool as its storage and graphing engine, and provides a CGI script for viewing the results.
jmxtrans is effectively the missing connector between JMX and whatever logging or graphing package that you can dream up. jmxtrans is very powerful tool that reads JSON configuration files specifying servers/ports and JMX domains/attributes and then outputs the data in whatever format you want via special "Writer" objects that you can code up yourself. It does this with a very efficient engine design that will scale to querying literally thousands of machines. The core engine is pretty solid and writers are included for cacti/rrdtool, graphite, and stdout.