File extension smf is used by following file type(s):

File extension smf file type 1 description:
OpenOffice.org formula file

File extension used by OpenOffice.org and StarOffice. The MIME type application/vnd.stardivision.math is used by StarOffice version 5.x.

Programs
that open smf files:
LibreOffice (multiplatform software)
NeoOffice (Apple OS X)
OpenOffice.org (multiplatform software)
PrimoOnline (Microsoft Windows)
StarOffice (multiplatform software)

 

File extension smf file type 2 description:
Standard MIDI file format

The SMF file extension is used for Standard MIDI format.

Musical Instrument Digital Interface (MIDI) is a standard protocol for the interchange of musical information between musical instruments, synthesizers, and computers. This standard defines the codes for a musical event that include the start of a note, its pitch, length, volume, and musical attributes, such as vibrato. It also defines codes for various button, dial, and pedal adjustments that are used on synthesizers.

The Standard MIDI Files (SMF) Specification was developed in 1990 for file exchange between MIDI sequencers, and quickly became a popular format for distributing music. This format is different from native MIDI protocol, because the events are time-stamped for playback in the proper sequence. 

Standard MIDI Files come in two basic varieties: a Type 1 file, and a Type 0 file (a Type 2 was also specified originally but never really caught on, so we won't spend any time discussing it here). In a Type 1 file individual parts are saved on different tracks within the sequence. In a Type 0 file everything is merged onto a single track. 

MIME: audio/mid

Programs
that open smf files:
Apple QuickTime (Microsoft Windows)
Apple QuickTime for Mac (Apple OS X)

 

File extension smf file type 3 description:
StarOffice StarMath file

File created by StarOffice StarMath (version 2.0 - 5.0).

Programs
that open smf files:
PrimoOnline (Microsoft Windows)
StarOffice (multiplatform software)

 

File extension smf file type 4 description:
System Monitor session

File extension used by System Monitor.

Mime: text/plain

Programs
that open smf files:
System Monitor (Microsoft Windows)