GNU Octave is a high-level language, primarily intended for numerical computations. It provides a convenient interactive command line interface for solving linear and nonlinear problems numerically, and for performing other numerical experiments. It may also be used as a batch-oriented language for data processing.
GNU Octave (Web Link)
Octave Programming Tutorial (Web Link 1)
Octave Programming Tutorial (Web Link 2)
Java is a programming language expressly designed for use in the distributed environment of the Internet. It was designed to have the "look and feel" of the C++ language, but it is simpler to use than C++ and enforces an object-oriented programming model. Java can be used to create complete applications that may run on a single computer or be distributed among servers and clients in a network. It can also be used to build a small application module or applet for use as part of a Web page. Applets make it possible for a Web page user to interact with the page.
Learn Java online...
Java Language Programming (Web Link)
Java SE downloads, including Java Development Kit 7
Java SE Downloads (Web Link)
Python is an easy to learn, powerful programming language. It has efficient high-level data structures and a simple but effective approach to object-oriented programming. Python’s elegant syntax and dynamic typing, together with its interpreted nature, make it an ideal language for scripting and rapid application development in many areas on most platforms.
Learn Python (Web Link)