A Backpropagation Network library written in C. There is also a ruby extension wrapper.
Getting started with Ruby extension:
$ git clone https://github.com/jpmec/ann.git
$ cd ann/backprop/src/ruby
$ rake
This should build and install the backproprb gem.
A simple interactive example:
# start irb
$ irb
# require the gem
> require 'backproprb'
# create a new network with 1 byte input, 1 byte output and 2 layers (i.e. 1 hidden layer)
> net = Backproprb::Network.new 1, 1, 2
# randomize the network with initial seed of 0
> net.randomize 0
# convert network to ruby hash
> net.to_hash