Perl 5, 1 bytes
Includes +1 for -v
(the body is empty). This includes both perl and Perl. But I'm going to assume the language name is perl from here on. It's what perl's own version string says the name is after all.
This is of course totally boring. Somewhat more interesting:
Perl 5, 6 bytes
say$^X
This assumes the name of the executable is named contains perl. I've yet to see an install where this is not so.
Perl 5, 11 bytes
say"\LPERL"
Uses the fact that case variations don't count. I couldn't use lc because it contains l. Still boring
Perl 5, 12 bytes
say FSDZ^6x4
This one clean but long