According to Erica:
“AirFlick provides another kind of service. Instead of substituting for an Apple TV, it transmits data to any ATV 2 (or any Mac running AirPlayer).
AirFlick offers the potential of real-time transcoding of otherwise unsupported file types into Apple TV-compatible data. It also allows you to open videos located on the Internet by pasting a URL and clicking the play button. I was able to watch a number of Internet Archive (archive.org) mp4 videos on a big screen TV by browsing that website, selecting URLs, and opening them with AirFlick.
AirFlick works by transforming your Mac into a web browser, the same way AirPlay works on your iPhone or other iOS device. For Mac-based files, AirFlick tells your Apple TV to connect to a local URL and serves the data that the Apple TV plays back. So long as those files are in a supported format such as mp4, m4v, mp3, etc, the Apple TV can read and display the file data.
The 0.01 release of AirFlick is quite alpha — so expect a few bugs along the way. If your Apple TV reports errors, you can always use your menu button (as I show in the video) to try connecting again.”