A little over a year ago, YouTube launched Creative Commons on YouTube, and officially allowed uploaders to ad a Creative Commons Attribution license (CC BY) to their videos. At the launch, the CC library consisted of just over 10,000 videos from organizations like C-SPAN, PublicResource, and Al Jazeera.

Today, YouTube tells us that there are now 4 million Creative Commons videos in their library, which means that YouTube is the number one place to go on the web to find video to “reuse, remix, and reimagine.”

From the YouTube blog:

Since the Creative Commons video library launch on YouTube a year ago, you’ve added more than 40 years’ worth of video to the mix. Anyone, anywhere can edit, build on and republish the library’s videos for free thanks to the Creative Commons Attribution license, otherwise known as CC BY.

Do you need a professional opening for your San Francisco vacation video? Perhaps some gorgeous footage of the moon for your science project? How about a squirrel eating a walnut to accompany your hot new dubstep track? All of this and more is available to inspire and add to your unique creation. Thanks to CC BY, it’s easy to borrow footage from other people’s videos and insert it into your own, because the license grants you the specific permissions to do so as long as you give credit to the original creator.

To make your video available to the Creative Commons, it’s as simple as clicking this option when uploading:

And starting today, you can switch over your default to CC BY, meaning that all of your future uploads will appear in the Creative Commons library.