MrSpidey is an interactive, static debugger for Scheme designed to help programmers understand and debug complex programs. It automatically infers information about the run-time behavior of programs, and uses this information to identify potential ``danger-points'' in those programs. Specifically, MrSpidey:
MrSpidey supports almost all of the constructs and procedures found DrScheme's R4RS+ language level. This language levels extends R4RS Scheme with structures, a module system, an object system, and a GUI toolbox. For further information on the technology underlying MrSpidey, see [1, 3, 4, 5, 2].