scheme PLT Scheme(DrScheme) is an interactive, integrated, graphical programming environment for the Scheme, MzScheme, and MrEd programming languages. PLT Scheme provides source highlighting for syntax and run-time errors, support for multiple language levels, an algebraic stepper, objects, modules, a GUI library, TCP/IP, and much more. It includes an extensive, hyper-linked help system called Help Desk. Support GC backtrace dumps Compile and install additional executables which use the conservative garbage collector Add support for compiling to the low-level virtual machine (llvm)