For only twenty years old, develop normally (for the film type, assuming you can find times). Yes, ideally in a low-fog developer like HC-110, though D-23 works pretty well, too. If you have the option, develop as cold as you can, down to about 60F for most developers (as low as 55F for D-23), and compensate temperature with extra time; the lower temperature will usually help minimize fog. Fog shouldn't be a huge issue with film only twenty years after exposure (as others have said), unless it was stored in a car trunk or on top of a water heater.
Or sell it on eBay; found film has done well there (I've bought several cameras just for the roll of film I could see had been left behind).