RubyNEAT is the world's first (and currently only) implementation of the NEAT algorithm in the Ruby programming language. RubyNEAT leverages some of the benefits of Ruby, such as metaprogramming, to implement activation of the Neural Net.
Basically, the Neural Nets in RubyNEAT manifests themselves in the Phenotypes as functional programs – of a sort. You may think of it as an application of Genetic Programming techniques to resolving the NEAT algorithm. As such, once fit Critters (neural nets) are found, they may be extracted as pure Ruby code, not needing the RubyNEAT engine for activation.