LispWorks is computer software, a proprietary implementation and integrated development environment (IDE) for the programming language Common Lisp. LispWorks was developed by the UK software company Harlequin Ltd., and first published in 1989. Harlequin ultimately spun off its Lisp division as Xanalys Ltd., which took over management and rights to LispWorks. In January 2005, the Xanalys Lisp team formed LispWorks Ltd. to market, develop, and support the software. LispWorks's features include: