Serato’s ability to work with Quartz Composer opens up some unique possibilities for audiovisual DJ sets. I could describe what those are, but here Venus Rollergirl shows them off in Serato Scratch, as it’s easier to see than talk about. (That’s not to be confused with Serato DJ, now a separate product.)

In this case, Serato is working with the VIDEO-SL plug-in, though you could use Mix Emergency for the same functionality. As I’ve said before, this is something of a stand-apart feature for Serato DJing in general, though one that might have only niche appeal. (I’d love to see more use of it.) It’s an old thread, but this 2009 discussion offers more details and includes more free downloads:
Video-SL 1.1 Quartz Composer Support

The video is an offering from iloveqc, an upstart Quartz Composer resource that offers tutorials, downloads, and Final Cut integration with the interactive visual tool Apple bundles with OS X.

Most interesting of these so far is a Final Cut Pro X loader that allows you to manipulate 3D files inside your video sets. (That one isn’t free.) We’ll be watching to see how this site evolves.