The ESP package contains the source code for the Enforced Sup-Populations system written in Java. This package is a nearly a direct port of the ESP C++ package available on this page. It should be easily portable although C++ is approximately 2.5 times faster.
Version 1.1 fixes some bugs in version 1.0 that prevented the use of recurrent networks. Now Simple Recurrent Networks, Second Order Recurrent Networks and Fully Recurrent Networks all work.