I'm considering entering Plot3d in the contest.

I'm posting to hopefully get some feedback about the program,
maybe some folks can also test it and offer helpful comments.
The program download is at http://www.plot3d.net/download.html.

Plot3d is a  simple 2D/3D mathematical function graphing program for Windows and
uses the OpenGL library it was compiled with C++ Builder version 5.

For entry it probably would be under the academic/educational software
category. 

The program can graph functions of the type y=f(x) and z=f(x,y).
In creating this program my goal was to keep it easy to use
so that someone can begin graphing functions in a minimal amount of time.
Also I wanted to try and produce high fidelity images.
OpenGL provides a fairly easy and very powerful rendering library with
very wide hardware support.

Still a few people have reported problems with the program not looking right.
Also received a couple of reports of floating point errors.
I think these are usually video card issues.
I haven't been able to duplicate these errors myself,
so it helps to have updated drivers for your computers video card.
Very old computers or very generic inexpensive video cards might
be the problem, feedback about this would be very helpful.

The program is still under development and there are certainly a great
many features it needs and that would be nice to add to it.
For example parametric graphs would be very nice, also the ability to have
more than one graph on the same window at a time.
The 2d grapher is very functional but still needs greater ability for
the user to customize the graph, also an adaptive plotting algorithm
would be very nice so the 2d grapher could better deal with discontinous
functions.
As was repeated on here somewhere, software is never really finished so we
continue to prod along.
The next issue I plan to concentrate on is to have the program normalize the
surface normals instead of having OpenGL do the normalization.
This would delay the initial drawing of a graph just a small amount, but
it would make all the redraws after that faster.

I hope people find the program useful. Let me know what you think.
best regards,

Marco