Executables within the JDK and JRE
The JRE's bin directory
We certainly know common executables like javac.exe and java.exe - but when looking into the bin directories of a JRE or JDK installation, there are a lot more executables. What is their purpose? Lets first check the JRE - the following executables are contained in an JRE's bin directory, and in most cases they are also replicated in the bin directory of the JDK:
Java application launchers
The console applications java launcher. Starts a Java Virtual Machine process and launches a Java application. On MS-Windows, this executable opens a console window.
Same as java.exe, but does not open a console window. This is the launcher which is usually used to run GUI based applications on MS-Windows.
The java webstart executable. This is the launcher which is executed by the browser when a .jnlp file has been clicked.
Combined applet and Webstart launcher, used by Webstart as of 7u65. Only contained in the JRE, but not in the JDK bin directory.
Java Management console - only contained in the JRE, but not in the JDK bin directory. Launches the management console which can also be started through the operating system's control panel. Used to define global properties for the JRE, such as the security level.
RMI and CORBA related
This is a launcher which was meant to be used for RMI-CGI gateways, but it is broken and should be removed. See bugs.java.com/bugdatabase/view_bug.do and stackoverflow.com/questions/25055466/what-is-java-rmi-exe for more information.
Starts the activation system daemon. See the tutorial at docs.oracle.com/javase/8/docs/technotes/guides/rmi/activation/overview.html for more information.
Starts the RMI registry naming service. RMI objects can register themselves with this service so that RMI clients can look up the objects by their name.
The CORBA object request broker daemon.
Standalone CORBA naming service.
Command line interface to register, unregister, startup and shutdown a persistent CORBA server.
Command line tool to manage cryptographic keys and certificates.
Command line tool to obtain Kerberos tickets.
Command line tool to list entries from the Kerberos credential cache and key table.
Command line tool to manage entries in the Kerberos key table.
GUI tool to edit java policy files which are used by the Java 2 Security Manager.
The Java update agent. This application is responsible to check for JRE updates. Only contained in the JRE bin directory, not in the JDK.
Enables or disables the Java Access Bridge. This allows functionality provided by the Java Accessibility API to be avilable to assistive technologies on MS-Windows. See docs.oracle.com/javase/7/docs/technotes/guides/access/enable_and_test.html for more information.