This paper describes the teaching of OpenGL shaders with hands-on a program called glman. Hands-on education is at its best when the students’ experimental feedback loop is very fast. glman allows students to create a shader scene description file which not only creates the 3D scene, but creates an interactive user interface to adjust parameters. Our experience in an experimental class taught in Spring 2006 is that glman is flexible enough to demonstrate and experiment with many shader concepts, and creates a fast learning curve for the students.