DrScheme is an interactive, integrated, graphical programming environment for the Scheme, MzScheme, and MrEd programming languages.
DrScheme 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, available from the Help menu. Tour of DrScheme describes many of these features in greater detail.
You can enhance DrScheme with many add-ons, including MrFlow, a static debugger, and MysterX, which adds COM support under Windows.
Operating System Support: Mac OS X 10.5 Intel, Mac OS X 10.5 PPC