Wolfram Mathematica v7.0

Description:
If you're doing anything technical, think Mathematica - not just for computation, but for modeling, simulation, visualization, development, documentation, and deployment.

Why Mathematica? Because this one integrated system delivers unprecedented workflow, coherence, reliability, and innovation.

Rather than different toolkits for different jobs, Mathematica has been built ground-up over nearly 20 years to deliver one vision: the ultimate technical application and environment.

Following closely on the dramatic reinvention of Mathematica in 2007, Mathematica 7 continues the momentum of innovation to deliver an array of new capabilities, greatly extending the state of the art in many areas, and bringing a dozen major new application fields into the integrated framework of Mathematica.

More info: http://www.wolfram.com/products/mathematica/index.html