Does anyone know of a library with a working implementation of backpropagation through time? Any of Java/Python/C#/VB.NET/F# (preferably the last one) will do!
I've had good experiences with Weka - In my view one of the best and almost certainly the most comprehensive general purpose machine learning libraries around.
You could certainly do BPTT with Weka - you may find a ready made classifier that does what you need but even if not you can just chain a few normal backpropagation units together as per the very good wikipedia article on BPTT