I'm looking at getting a kegerator since bottling kinda sucks. I'm on Amazon and they have a fridge that can take:"1/2 barrels / Full Size Kegs (15.5gal), 1/4 barrels / Ponies (7.75gal)". I've only heard of corny kegs being used with homebrew. What's the difference between a corny and a pony keg?
I always thought standard quarter barrels were ponies. And according to Micromatic a Pony Keg IS a standard quarter barrel. The tall quarters are called "slim quarters".
Here is a link: Micromatic Chart
Ponies, generally, are just tall, skinny quarter-barrels. They look like corny kegs, but have Sankey, or other commercial beer fittings. Sometimes the standard squat quarter barrel is also referred to as a "pony" keg. I think that designation is largely regional.
Cornelius kegs come from the commercial soft drink industry and are usually 5 gallons, although there are 2.5 gallon, 3 gallon and I have seen a 7 gallon Corny keg. Anything but the five is rare and I would have called the 7 a rumor if I hadn't seen one once. But only once.