$LANGUAGE: Identifier for current language
This expands to an identifier that denotes the current language, as follows:
Language $LANGUAGEC $CC++ $CPPFortran $NFortran-90 $N90Ratfor $RRatfor-90 $R90TeX $XVERBATIM $V
Note that this outputs identifiers, not FWEB macros. They are intended
to be used in $IF or $IFELSE statements such as
$IF($LANGUAGE==$C, C-text, other-text)
For multiway switches, the $LANGUAGE_NUM built-in is more useful;
see $LANGUAGE_NUM.