MathILy is an intensive residential summer program for mathematically excellent secondary students. Five weeks of maximized mathematical marvelousness featuring exploration and creation of mathematics, problem-solving skills development, advanced mathematics learning, and overall thinking skills enhancement. The program is designed for students with insatiable curiosity about mathematics who are creative and enthusiastic in their approaches to learning. Participants come from all over the United States and sometimes the world. The program promises focused and individually tailored effort that elicits massive learning, enormous fun, and significant personal growth.