Autocall is calling automatically zero param methods. This avoids typing lots of empty paren sets () :

Autocall ON :

Get the active application

NSWorkspace.sharedWorkspace.activeApplication

Autocall OFF :

Get the active application

NSWorkspace.sharedWorkspace().activeApplication()

By default Autocall is ON. To switch it off, use

[[JSCocoaController sharedController] setUseAutoCall:NO];

You'll get errors if you use parens while autocall is ON.