Mertvoprog is an esotherical visual programming language intended for fun learning uh, whatever, it's useless.
The name is a reference to the derogative name of the Metaprog language (Deadprog in Ukrainian Russian).
There is intentionally no any manual because the language is meant to be intuitive (like any visual programming language should be, right?) Just drop the bones and see what happens. The only hint is that you should try clicking anywhere with both left and right mouse buttons, sometimes even the middle one!