COBOL
COBOL (COmmon Business-Oriented Language) dates back to the 1950s, and started to be thought of as clunky and archaic by many programmers not long after that. Nevertheless, it got wide use in big-corporate data processing applications playing a major part in the infrastructure of the world's economy, so it's not going away any time soon; it remains in use to this day, and has even spawned an object-oriented version (letting people be both archaic and up-to-date at once). There was a temporary major demand for COBOL programmers around 1999 to fix Y2K-related bugs in various application packages in the language whose developers never dreamed they'd still be in use at the end of the century and need to cope with the year "00" coming after "99". (Memory was too expensive in the early days of computing to splurge for an extra two digits in years.)