I have a new language. Its name is "kuna". It is not published yet. It resembles perkun, but does not keep all its model in memory. Instead it calculates the model value from certain rules whenever it is necessary. It is therefore a little stronger than perkun. It allows more input and hidden variables.
In order to create kuna I used some of the perkun code. Especially the parser and the optimization algorithm are taken almost directly from perkun. The syntax is similar. Kuna comes as a library, just like perkun, so it is possible to use it in your own C++ programs.
A kuna program consists of three sections - values, variables and knowledge (describing both the payoff and model).