UK software house Harlequin Ltd of Cambridge, chose the recent International Joint Conference on Artificial Intelligence in Detroit as the launchpad for a new development environment for Common Lisp. LispWorks is a package integrating the ANSI standard Common Lisp with an object-oriented environment based on the Common Lisp Object System, along with lightweight processes, X-Window, and monochrome and colour graphics. With all the elements written in Lisp, Harlequin claims that programming tools, compilation and interpretation and garbage collection are all closely embedded into the environment. Tools include an EMACS-style Lisp editor, full source level debugging and a hypertext facility for on-line documentation. The user interface is an optimised version of CLX, the standard Common Lisp interface to the X Window System, and there is also an implementation of the CLUE Common Lisp User Interface Environment. Available on a wide range of hardware, LispWorks costs UKP5,000 for a single user version on a Sun Microsystems workstation, although low-cost delivery systems sufficient to run applications are also offered. Future releases will include a Distillation Facility for removing unnecessary code in run-time application systems, and a Postscript-based model with active windowing is also planned. Harlequin has also developed the ScriptWorks high performance PostScript clone, which includes facilities for previewing and windowing.