For one of my classes, I’ve been playing around with GNU Octave. Octave is a free and open source program very similar to Matlab. From the Octave web site:
GNU Octave is a high-level language, primarily intended for numerical computations. It provides a convenient command line interface for solving linear and nonlinear problems numerically, and for performing other numerical experiments using a language that is mostly compatible with Matlab. It may also be used as a batch-oriented language.
Sometimes, I’m away from one of my own computers, but I still want to do a little bit of Octave work. I’ve written just a tad bit of PHP code that allows me to access Octave over the web. You can type in your Octave code, and it will return the output results and output graph.
Because I would rather not hammer my server with octave requests, I won’t be showing a demo, but I’m making all the source code available, and you can put it on your own server and try it yourself. I’m hosting the project at Google Code: http://code.google.com/p/web-octave/