In his book, "The Clean Coder", Robert C. Martin mentions programming Kata as small exercises to practice programming. He states programming needs practice just like any other profession:
Musicians rehearse scales. Football players run through tires. Doctors practice sutures and surgical techniques. Lawyers practice arguments. Soldiers rehearse missions. When performance matters, professionals practice.
This is my collection of Kata for my own programming practice. See the katas folder for the list of katas.