An XML-based symbolic computer language, interpreter, and corresponding execution environments are disclosed. The XML-based symbolic computer language, called "OLIN" (One Language Intelligent Network) enables a computer program to be written as an XML-compliant document. OLIN programs are interpreted by an interpreter by parsing the XML content to extract symbolic expressions embedded therein, and evaluating those symbolic expressions. The XML-based symbolic computer language is object-oriented and is based on inherent principles of the LISP programming language. Accordingly, code and data are treated the same. The language provides built-in structures and functions for implementing neural networks and genetic programming. OLIN programs may be executed by a single computer, or via a multiprocessing environment, including distributing processing environments and multiprocessor computers.