• Ability to plug in your own pattern matching engine, if the standard one is not sufficient for your requirements.
• Optional namespace-aware processing, so that you can define rules that are relevant only to a particular XML namespace.
• Encapsulation of Rules into RuleSets that can be easily and conveniently reused in more than one application that requires the same type of processing.

• Building scripting languages that interact with the Java object model (such as the Bean Scripting Framework).
• Building template language processors for web presentation and similar uses (such as JSP or Velocity).
• Building custom tag libraries for JSP and XSP environments (such as Jakarta Taglibs, Struts, Cocoon).
• Consuming XML-based configuration resources (such as Ant build scripts, web application deployment descriptors, Tomcat's server.xml file).

SIGAR - System Information Gatherer And Reporter

• System memory, swap, cpu, load average, uptime, logins
• Per-process memory, cpu, credential info, state, arguments, environment, open files
• File system detection and metrics
• Network interface detection, configuration info and metrics
• TCP and UDP connection tables
• Network route table

• configuration and dependency management code
• a general logging framework
• text utilities
• user interface classes for displaying information about applications
• custom layout managers
• a date chooser panel
• serialization utilities