Enlen

Enlen is a professional interactive toolkit for algebraic topology and homotopy theory. It brings together Eilenberg–MacLane spaces, classifying spaces, Postnikov towers, Moore spaces, and fibrations in a unified workspace—with adjustable parameters, live computation, and exportable results.

Whether you are a student learning obstruction theory or a researcher who needs quick access to cohomology rings, obstruction classes, and long exact sequence fragments, Enlen offers a structured, hands-on environment. It is not a full computer algebra system, but it is genuinely useful for lectures, problem sets, and concept exploration.