I've just posted a light weight C++ library that implements a three layer feed-forward back propagation neural network simulator on github. The repository is here: https://github.com/nickoppen/eNNpi.git.
I developed this version on the pi using the C++ standard library. This is an update of a version that I wrote a couple of years ago and is a very C++ oriented solution. There are classes for links, nodes, layers using templates, multiple inheritance and pretty much every C++ feature I know.
My intention is to use this as a base version and from which I'll develop a version for the parallella when it arrives. The next thing I'll work on is a matrix based implementation along the lines of the design outlined in the two previous posts on this blog.
If you want to download it and have a play please do. I hope my documentation is clear enough to get you started.
One caveat though. I found github really confusing. If you are not familiar with it, downloading the files and not using git locally is probably the best way to go. Also, please don't post git or github questions - the answer will be "I have NO idea".
Please comment if you find any problems either on this post or on the repository wiki.
Thanks and have fun.
PS I just managed to get the Shuttle Statlog data uploaded. There are four training sets and one test set, the original data and transformed data in an open office spreadsheet and two scripts, one for create/train/save and one for test.