CREP is designed to deal with categories whose morphism spaces are finite-dimensional over a field k. The main example of a category with this property is the category of finite-dimensional representations of an associative unital k-algebra. For many applications even the algebra itself may be assumed to be of finite dimension over k. Popular examples for algebras of this kind are the group algebras for finite groups or the finite-dimensional factor algebras of polynomial algebras. If one wants to approach categories with finite-dimensional morphism spaces, the language of quivers is an appropriate way. Recall that quiver is a shorthand for directed graph with possibly multiple edges and loops. This is a purely combinatorial object inviting to computational access. The aim of CREP is to provide algorithms using this access for research and teaching. The system is being designed along the lines of current research. On the other hand, there are many basic functions and, in particular. graphical interfaces which are instructive and useful for students and neophytes. The code of CREP is freely available. People are invited to contribute.