Last month, Wolfram Research released Mathematica 8.  Swarthmore ITS has the new edition available for download for faculty, staff, and students here:
Download Mathematica 8 (Swarthmore username and password required).  We have versions for Windows, Macintosh, and Linux.

From Wolfram’s website, here are the top 8 reasons to upgrade:

1. Enter your queries in plain English using new free-form linguistic input
2. Access more than 10 trillion sets of curated, up-to-date, and ready-to-use data
3. Import all your data using a wider array of import/export formats
4. Use the broadest statistics and data visualization capabilities on the market
5. Choose from a full suite of engineering tools, such as wavelets and control systems
6. Use more powerful image processing and analysis capabilities
7. Create interactive tools for rapid exploration of your ideas
8. Develop faster and more powerful applications

Mathematica 8’s free-form input is a new way to interact with Mathematica.  For example, typing

= sum integers from 1 to 100

returns

5050

and typing

= factor -2 a+2 x+a x-x^2+a x^2-x^3

returns

(a -x) (-1 + x) (2 + x)

For the folks interested in higher performance, Mathematica is GPU enabled using CUDA or OpenCL.  It is also possible to compile your programs to C code.

For the social sciences, Mathematica has better statistical and financial charting along with the ability to access public data sets.  For example, you can get weather or census information from a single line Mathematica code.