Ruddy spent five years at Goodison after being plucked from Cambridge United by Moyes in 2005.
But the 26-year-old had just 80 minutes of top-flight action for the Toffees during that time — largely due to the form of Tim Howard.
Moyes said: “I’m a little surprised at how he has developed.
“It was always going to be difficult for him to get games in front of Tim Howard. But he’s done great. You rarely put young keepers in the team and when he went to Norwich it looked like a chance for him. He hasn’t half take it.
“He’s progressed under Paul Lambert and now Chris Hughton. He’s in and around the England squad so good luck to him.
“He’s really done very well.”