The creator of the Gradual Interface Forget wanted people to pronounce it with a J literally because he wanted it to use the name recognition of the peanut butter - and I don't exactly care about their profits or about copyright, but it's a bad reason.
With a hard "guh" sound, because that's what I grew up with.
JIF is peanut butter
GIF is Graphic Interchange Format
The creator of the Gradual Interface Forget wanted people to pronounce it with a J literally because he wanted it to use the name recognition of the peanut butter - and I don't exactly care about their profits or about copyright, but it's a bad reason.