JMX (Java Management Extensions) is a mechanism for managing and monitoring Java applications, system objects, and devices. It represents resources as MBean (Managed Bean) objects, providing a window to read and interact with the running application. JConsole is the canonical graphical monitoring tool for applications running in the JVM, but it has limitations due to its resource-intensive nature and requirement of X11. The Datadog Agent provides an alternative solution with tools like Jmxterm and JMXFetch, which offer lightweight, full-featured JMX consoles without external dependencies. Jmxterm allows users to connect to monitor Java applications, while JMXFetch enables the collection of metrics and provides a comprehensive view of system data. These tools can be used to implement ongoing monitoring, spot trends, and diagnose issues in Java applications with minimal setup.