Free chemical equation software for windows

Caerfai Chemical Simulation is a simple tool that is trying to simulate chemical reactions.
The model is much too simple to be useful, but it gives some nice images and animations. Source is included and offers a nice starting point for similar endevours.
Every atom in the simulation is a moving ball which bounces on other atoms and the edges of the window. Atoms can bind to each other, similar to how things work in reality. Well start out with just radicals and build molecules from there. In reality, this is pretty much where it stops, but I break up the molecules everytime they bounce, in order to create more interesting structures. Less chemical, but more fun.
Breaking up the molecules when in reality they would break, would complicate the program a lot beyond the current few hundred lines and anyway, the reaction would occur almost never, as it happens in reality (but there the molecules go so fast that it seems quite quickly, especially if your sleeves have gotten on fire)

Quadratic Equation Solver 2 is a simple yet very useful math application that calculates every possible solution of a quadratic equation. It is fast, easy-to-use, and takes up very little hard disk space: 260k. It can be run on every Windows-based computer, even on DOS.

This calculator allows natural entry of equations (i.e. 17-(9*8) - 7 + 34.23).
Metalogic Calculator is an equation solver utility that shows you the exact steps it followed.
Then it goes beyond just giving you a result, the "steps" box, shows you how it solved the equation step by step.
Results are given simultaneously in dec/hex/oct/bin. Great for students and home use.
It takes the mystery out of solving complex equations.
Enhancements:
- Improved UI, maximizable and smaller installer