MATLAB - A high-level language and interactive environment for numerical computation, visualization, and programming
Toggl - Toggl is an online time tracking tool. It features 1-click time tracking and helps you see where your time goes. Free and paid versions are available.
GNU Octave - GNU Octave is a programming language for scientific computing.
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
Wolfram Mathematica - Mathematica has characterized the cutting edge in specialized processing—and gave the chief calculation environment to a large number of pioneers, instructors, understudies, and others around the globe.
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.