Sergey Kolos Ver 0.9.375 Cusp is an IDE for programming in lisp (Common Lisp flavor). It comes prepackaged with SBCL and a set of tested libraries. Its package contains everything for it to work and Cusp doesn't have any external dependencies (other than Eclipse). Cusp contains all the basic features you expect from modern IDE and some more: code formatting and coloring, folding, outline,