GAUSS is a mathematical and statistical programming language for doing economic and econometric research.
Geometer’s Sketchpad allows you to construct figures, diagrams and mathematics concepts, as well as complex geometrical constructions.
Google Earth is a map of the world which allows you to zoom in and view satellite imagery.
gretl is a program for econometric analysis.
Maple is a computer algebra system that helps you analyse, explore, visualize, and solve mathematical problems.
Mathematica is a program and computer language for use in mathematical applications.
Scientific Workplace + Beamer allows you to create, edit and typeset mathematical and scientific text.
Texmaker is a Latex editor used to write well structured documents.