This is the Source Filmmaker. It lets you use your PC to create animated short films. And it's entirely free.
This is the tool that Valve used to create all nine of its "Meet the Team" short films. Will yours be as hilarious? Only time will tell.
"The goal of the SFM was to develop a story telling tool that allowed us to create computer animated movies more efficiently, and with greater creative freedom," said Valve designer Bay Raitt in a press release today. "Over the past five years, we've produced more than 50 animated shorts with the SFM. The Source Filmmaker will allow our community to create their own movies in Team Fortress 2 and in their own Source SDK-created mods."
Valve will release the Source Filmmaker later this year on Steam. Here's the official website, in case you want to sign up for the beta.