PLT Scheme is an umbrella name for a family of implementations of the Scheme programming language.

PLT is the group of people who produce PLT Scheme. We welcome applications from students interested in graduate study.

DrScheme is the primary PLT Scheme implementation.

TeachScheme! is a PLT project to turn Computing and Programming into an indispensable part of the liberal arts curriculum.

How to Design Programs (HtDP) is a textbook for introductory programming that was written by several PLT members.

PLaneT is PLT's centralized package distribution system. Visit for a list of user-contributed packages.

How to Use Scheme (HtUS) is a book about using PLT Scheme for everyday programming tasks. (Still a work in progress.)

MzScheme is the lightweight, embeddable, scripting-friendly PLT Scheme implementation.