Pylot - Open Source Software testing tool

Pylot is a open source performance and scalability testing tool which runs HTTP load tests and generates concurrent load (HTTP Requests), verifies server responses, and produces reports with metrics.

Physlets

"Physlet" is short for "Physics Applets." This collection of Java-based applets demonstrates a variety of physical laws and for teachers and students.

SpeedCrunch

Open source desktop calculator

A fast, high-precision and powerful desktop calculator.
Using SpeedCrunch you type the expression that you want to calculate and press Enter. You can paste the expression from the clipboard (that you copied from somewhere else) and you can copy the last calculation result to the clipboard using Ctrl+R.

KAlgebra

Open Source Calculator

KAlgebra is a calculator with symbolic and analysis features that lets you plot 2D and 3D functions as well as to easily calculate mathematical expressions. KAlgebra is a MathML-based graphic calculator, thought to bring to the user its power by solving expressions written in MathML or calculating converted common equations to MathML.