Greetings, nerds! I come bearing good news from the north. Alas, winter is still coming; but, before that gets here, Valve has made the first Portal completely free on Steam. You have until September 20th (next Tuesday) to take advantage of the offer.

And, yes, Portal is good for both the PC and Mac versions of the Steam platform.

What bizarre, mystical creature do you have to thank for this wondrous news? Valve is doing it as an education initiative. This whole thing is part of their Learn With Portals program. Here’s why the company is offering up this first person puzzler as a score for learning:

Intrigue. Engage. Inspire.

When we heard the buzz surrounding the new role video games are playing in education, we had to throw our hat in the ring. Today, innovative educators are finding ways to incorporate Portal™ and Portal 2 into their classrooms—helping teach physics and critical-thinking skills. It’s eye-opening to see how video games can be used in amazing and unexpected ways to help educate our next generation.

One of the biggest challenges in teaching science, technology, engineering, and math is capturing the students’ imaginations long enough for them to see all of the possibilities that lie ahead.

Using interactive tools like the Portal series to draw them in makes physics, math, logic, spatial reasoning, probability, and problem-solving interesting, cool, and fun which gets us one step closer to our goal—engaged, thoughtful kids!

If I ever had a teacher willing to let me sit down and apply the process of reasoning to a game like Portal, I never would have left middle school … ever. The closest thing I ever got to a teacher like that was when my Health Ed instructor forgot he left one of the computers on and running a copy of Lemmings.

Good times.

September 20th is right around the corner. Be sure to pick Portal up from Steam by then if you don’t already own it.