LibBWEntrainment is a Free and Open Source Brainwave Entrainment Library for Java.
*** It is not a standalone application. ***
The library is very flexible, allowing different types of renderers (isochronic, binaural, ...) as well as multiple output devices (speakers, file, socket or even screen), and it can easily be ported to other languages because it doesn't use any proprietary Java feature.
Current features:
-Javadoc and examples
-Extremely lightweight, yet flexible
-Easy to use...