I asked Les if he'd heard the word used before and he answered, "I think it's an acronym but I don't know what it stands for, but I've heard it pronounced with both 'g' and 'j' sounds."
In researching, I learned that GIF stands for GRAPHIC INTERCHANGE FORMAT. Merriam-Webster definition: "noun; a computer file format for the compression and storage of visual digital information; also, an image or video stored in this format. First known usage: 1987."
See the definition from the
GIFs are image files that are compressed to reduce transfer times. The creators of the format, Bob Berry and Steve Wilhite, claim that the soft 'g' sound is correct. One said, "Choosy programmers choose GIF, a play on the peanut butter commercials where 'Choosy moms choose JIF' is used."