Gwydion Dylan is a portable, optimizing Dylan compiler written in Dylan. It was originally written by the Gwydion Group at CMU and is now maintained by volunteers. Eventually, Gwydion Dylan is meant to become a top-notch tool for building complicated applications. Dylan is a dynamic, object-oriented language with four design goals: high performance, rapid prototyping, ease of use, and seamless support for using libraries written in C. Ports of Gwydion Dylan are available for many platforms.