.SIB File Extension
File TypeSibelius Score
File format categories include Binary, Text, XML, and Zip. The format of this file type has not been determined.
What is a SIB file?
Musical score created with Sibelius music notation software; may be composed using software or a MIDI input device; can be used to play software instruments, but does not contain actual audio data.
SIB files can also be exported as standard MIDI (.MID) files from within Sibelius.