Jconsole is a JMX-compliant monitoring tool. It uses the extensive JMX instrumentation of the Java virtual machine to provide information on performance and resource consumption of applications running on the Java platform.
X-develop, and its little brother CodeGuide, are commercial IDEs that are developed by Omnicore and respectively sell for $499 and $399. CodeGuide includes Java support, while X-develop also supports C# and Visual Basic on .NET and Mono. What sets them ap