$SoundDisplayFunction (Built-in Mathematica Symbol)

$SoundDisplayFunction gives the default setting for the option DisplayFunction in sound functions.

$SyntaxHandler (Built-in Mathematica Symbol)

$SyntaxHandler is a global variable which, if set, is applied to any input string that is found to contain a syntax error.

$SystemCharacterEncoding (Built-in Mathematica Symbol)

$SystemCharacterEncoding gives the default raw character encoding for the computer system on which Mathematica is being run.

$SystemID (Built-in Mathematica Symbol)

$SystemID is a short string that identifies the type of computer system on which Mathematica is being run.

$System (Built-in Mathematica Symbol)

$System is a string describing the type of computer system on which Mathematica is being run.

$SystemWordLength (Built-in Mathematica Symbol)

$SystemWordLength gives the effective number of bits in raw machine words on the computer system where Mathematica is running.

$TemporaryDirectory (Built-in Mathematica Symbol)

$TemporaryDirectory gives the main system directory for temporary files on your computer system.

$TimedOut (Built-in Mathematica Symbol)

$TimedOut is a special symbol returned by certain functions when an operation times out.

$TimeUnit (Built-in Mathematica Symbol)

$TimeUnit gives the minimum time interval in seconds recorded on your computer system.

$TimeZone (Built-in Mathematica Symbol)

$TimeZone gives the current time zone to assume for dates and times.