.SFIL File

The sfil file extension is related to system sounds used in Mac OS 7, 8 and 9. These were the sounds that the various system alerts and events caused.  There was a huge market amongst enthusiasts at one point for sound clips from Star Trek and various cartoon shows in the SFILl format to allow you to, for example, have Fred Flintstone go "Yabba-Dabba-Do!" when your file copy completed.  Mac OS came bundled with an application to customize all system sounds. 

How to open:

These files are played automatically when some operation triggered them.

How to convert:

To convert to a .mov Quicktime file you open the .sfil file in the OS 9 QuickTime application (Version 6) in either Classic Mode or (providing you still have a PowerPC Mac that will boot into OS 9) in actual OS 9. QuickTime will present you with a "Convert" button that will turn the file into QuickTime Movie file that will play under OS X (I've tested up to 4.11 anyway). It will, annoyingly, not have an .mov extension but you can add that manually.