Stephen Wolfram, the scientist behind Wolfram Alpha, announced that the launch of Wolfram Alpha Pro, which he calls “the biggest single step in the development of Wolfram Alpha since its original introduction.”

I’d wager that there have been bigger steps in terms of getting people to actually use Wolfram Alpha – it’s integration with Siri. According to The New York Times, Siri accounts for about a quarter of its queries.

Wolfram Alpha Pro costs $4.99 a month ($2.99 for students).

“Over the two and a half years since we first launched, Wolfram|Alpha has been growing rapidly in content and capabilities,” says Wolfram. “But today’s introduction of Wolfram|Alpha Pro in effect adds a whole new model for interacting with Wolfram|Alpha—and brings all sorts of fundamentally new and remarkable capabilities.”

The pro version includes:

data in put
file upload
image input
data download
CDF interactivity
extra computation time
customizable graphs and tables
PDF/CDF report download
extended symbol keyboard
output zoom

Wolfram provides an extensive walkthrough of the new features on his blog.

“We’re certainly not finished with everything that’s possible, but already in the version of Wolfram|Alpha Pro that we’re releasing today, I think what we can do with data is pretty impressive,” he says. “Of course, it helps that we can build on all the sophisticated data and statistics-related capabilities that are now built in to Mathematica. And it also helps that we can make use of all the other parts of Wolfram|Alpha.”

The standard version of Wolfram Alpha will remain free.