Free Downloadable Physics Software

* see Matlab Clones for an explanation of the fact that Matlab is great, however it is not only "Expensive" but "costs a lot". Many of the programs listed here are able to do MatLab-like calculations.

Linux/Unix/FreeBSD etc

CASPOC
*** Although this is Windows software, I have had no problems with it running in Linux using the free Windows compatability layer WINE
Free demo version of multilevel model software. Includes a circuit level for the modeling of Switched Mode Power Supplies, a component level for the modeling of electrical machines / loads and a system level for the modeling of control algorithms.

Octave
A high-level language (very similar to Matlab), primarily intended for numerical computations. A free tool thats great for physicists.

Euler
I haven't tried this one, but it sounds similar to Octave and Scilab. The website says "Euler is not a MatLab clone, but similar to this program."

Scilab
A high-level language (very similar to Matlab&Octave), primarily intended for numerical computations. Includes a MAPLE interface.

Mac

Dynamic Analyzer
Designed to allow students to model physical systems and compare the models with experimental data.

Instructional Software by RW Tarara
A Saint Mary's professor makes several instructional packages available for free.

Scilab
A high-level language (very similar to Matlab&Octave), primarily intended for numerical computations. Includes a MAPLE interface.

Windows

Arbor Scientific
Software you can download and try-before-you-buy. Titles include: crocodile physics, interactive physics and oscillations & waves.

CASPOC
Free demo version of multilevel model software. Includes a circuit level for the modeling of Switched Mode Power Supplies, a component level for the modeling of electrical machines / loads and a system level for the modeling of control algorithms.

CyclePad
Enables students to construct and analyze a wide variety of thermodynamic cycles.

Euler
I haven't tried this one, but it sounds similar to Octave and Scilab. The website says "Euler is not a MatLab clone, but similar to this program."

Dynamic Analyzer
Designed to allow students to model physical systems and compare the models with experimental data.

Instructional Software by RW Tarara
A Saint Mary's professor makes several instructional packages available for free.

Octave
A high-level language (very similar to Matlab), primarily intended for numerical computations. A free tool thats great for physicists.

Physics Collisions Simulator
Shows balls that bounce around the screen and perform oblique collisions. Can be used to demonstrate ideal gas laws.

PowerCalc - Bicycle Physics Software
Estimate a riders power and calorific requirements, taking into account wind resistance, rolling resistance, transmission losses etc. Also, GearCalc

Raytrace
A raytracing program written for teachers of geometrical optics and optical designers who want a quick tool for checking out their ideas.

Reltran
Designed to be used by high school students. It includes, among others, calculations of wheel's diameters and number of teeth.

Scilab
A high-level language (very similar to Matlab&Octave), primarily intended for numerical computations. Includes a MAPLE interface.

Superposition
Allows students to investigate the superposition of two transverse traveling waves.

U of Arizona Math Software
Various software for math education.