Blink is a portable mixed-mode Java/native debugger for JNI (Java Native Interface) and Jeannie programs. Blink allows you to inspect Java and native program state while the JDB or the GDB shows only one of Java or the native program state. Blink is portable across different Java virtual machines, machine architectures and operating systems. Blink combines an existing portable Java debugger (JDB) and native debugger (GDB). These black-box sub-debuggers under the Blink control cooperate transparently with each other to create an illusion of a single mixed-mode Java/native debugger. The Blink user interface is similar to the command line interfaces in JDB and GDB. The Blink master script file (blink.sh) provides the same invocation command line syntax as JDB. The Blink commands within the debugging session are similar to these in JDB and the GDB. JDB and GDB users should be familiar with the Blink debugger. This user guide describes how to use the Blink mixed-mode Java/native debugger in practice.