This library provides a Java (JNI) interface to the Editline library, which is available on BSD systems and Mac OS X, and can be installed on most Linux systems. Editline is a replacement for the GNU Readline library, with a more liberal BSD-style license. Linking Editline into your code (and, similarly, using this Java interface to it) will not change the license you have assigned to your code.
Please see the Java EditLine web page for documentation and build instructions.