TidBITS:

Developed by Connectix, RAM Doubler was one of the most magical utilities of the early days of the Macintosh. As its name suggested, RAM Doubler promised to double the amount of usable RAM in your Mac, and amazingly, it generally delivered.

That was a big deal back in 1994 because RAM was shockingly expensive—$300 for an 8 MB SIMM at a time when I had 20 MB in my Centris 660AV. For $50, RAM Doubler would double whatever you had: 8 MB to 16 MB, or 20 MB to 40 MB. It was astonishing.

You young whippersnappers will now have to watch as us old farts exclaim, “I loved RAM Doubler!” It was freaking magic.