I will not write much, but just would like to let you know there is a new Perl module for Language Identification (Lingua::Identifier). It uses a neural network for the task (read this for details), with Math::Matrix::MaybeGSL, that will use Math::MatrixReal or Math::GSL::Matrix if it is installed. An extended version of the paper is being reviewed, and therefore I am not allowed to publish it here.