Prior to releasing Wolfram|Alpha into the world this past May, we launched the Wolfram|Alpha Blog. Since our welcome message on April 28, we’ve made 133 additional posts covering Wolfram|Alpha news, team member introductions, and “how-to’s” in a wide variety of areas, including finance, nutrition, chemistry, astronomy, math, travel, and even solving crossword puzzles.

As 2009 draws to a close we thought we’d reach into the archives to share with you some of this year’s most popular blog posts.

#### April

**Rack ’n’ Roll**

*Take a peek at our system administration team hard at work on one of the
many pre-launch projects. *Continue reading…

**May**

**The Secret Behind the Computational Engine in Wolfram|Alpha**

*Although it’s tempting to think of Wolfram|Alpha as a place to look up facts, that’s only part of the story. The thing that truly sets Wolfram|Alpha apart is that it is able to do sophisticated computations for you, both pure computations involving numbers or formulas you enter, and computations applied automatically to data called up from its repositories.
*

*Why does computation matter? Because computation is what turns generic information into specific answers.* Continue reading…

**Live, from Champaign!**

*Wolfram|Alpha just went live for the very first time, running all clusters.*

*This first run at testing Wolfram|Alpha in the real world is off to an auspicious start, although not surprisingly, we’re still working on some kinks, especially around logging.
*

*While we’re still in the early stages of this long-term project, it is really gratifying to finally have the opportunity to invite you to participate in this project with us. *Continue reading…

**June**

**Wolfram|Alpha Q&A Webcast**

*Stephen Wolfram shared the latest news and updates about Wolfram|Alpha and answered several users’ questions in a live webcast yesterday.*

* If you missed it, you can watch the recording here.* Continue reading… More »

We’re really catching the holiday spirit here at Wolfram|Alpha.

We recently announced our special holiday sale for the Wolfram|Alpha app. Now we are launching our first-ever Wolfram|Alpha “Holiday Tweet-a-Day” contest.

Here’s how it works.

From tomorrow, Tuesday, December 22, through Saturday, January 2, we’ll use Twitter to give away a gift a day. Be the first to retweet our “Holiday Tweet-a-Day” tweet and you get the prize! You can double your chances to win by following and playing along with Wolfram Research.

Start following us today so you don’t miss your chance to win with our Wolfram|Alpha “Holiday Tweet-a-Day” contest.

When we launched Wolfram|Alpha in May 2009, it already contained trillions of pieces of information—the result of nearly five years of sustained data-gathering, on top of more than two decades of formula and algorithm development in *Mathematica*. Since then, we’ve successfully released a new build of Wolfram|Alpha’s codebase each week, incorporating not only hundreds of minor behind-the-scenes enhancements and bug fixes, but also a steady stream of major new features and datasets.

We’ve highlighted some of these new additions in this blog, but many more have entered the system with little fanfare. As we near the end of 2009, we wanted to look back at seven months of new Wolfram|Alpha features and functionality.

Psychrometry deals with the thermodynamic properties of gas-vapor mixtures. Air-water vapor mixtures are the most common systems studied because of their importance in heating, ventilating, air conditioning, and weather reporting.

Students of engineering are introduced to the subtleties of psychrometry in their thermodynamics courses. But we are all exposed to psychrometry any time we watch weather reports on television. Your favorite meteorologist probably speaks about the relative humidity, dry bulb temperature, and dew point temperature.

Let’s start our exploration of psychrometry by querying “psychrometric properties“. Wolfram|Alpha returns a presentation of data for moist air, including a graph known as a psychrometric chart.