Crusher 01 was a holographic program created by Jack R. Crusher on stardate 25102.45.
Ten weeks after Wesley Crusher was born in 2348, his father recorded a message for his son, intending it to be a gift for him when he turned eighteen. It was seen by the father as the first of a series of messages; however, Jack never got the chance to make more messages.
In 2367, Wesley played the message, giving him a sense of closure with his deceased father. (TNG: "Family")