Very few languages that have been widely used ever truly die. FORTRAN, LISP, COBOL, BASIC, Pascal...these languages will continue to have commercial use for decades to come, albeit at a much smaller user community size.

This year, Smalltalk celebrates its 50th anniversary. The language is alive and well. It has thousands of commercial users around the globe supported by evergreen Smalltalk vendors like Cincom, Instantiations, and GemTalk. In fact, I've organized a birthday party for it: https://campsmalltalksupreme.wordpress.com/