What if your debugger could go "go backwards in time?" Would that make debugging easier? By simply recording all variable assignments, it is possible to do essentially this. This is the underlying idea for omniscient debugging. The amazing part is that significantly large programs can be debugged in this fashion -- Ant, JUnit, the debugger itself.
Returning from rave reviews in Europe (Ecole des mines de Nantes, INSA, ECOOP, AADEBUG, France! Sweden! Germany! Russia! Belgium! Estonia!), the ODB made its next public appearence at OOPSLA where it passed the $100 challenge (that was the amount offered for any bug it couldn't find). And now it will be a feature article in Doctor Dobbs Journal (just in time for my Nth birthday, 9 May 2005)! And just in time for its presentation on stage to thousands of screaming fans at JavaOne!
Life is good for the ODB and that's bad for bugs.
The debugger works by collecting "time stamps" which record everything that happens in a program. A GUI then allows you to navigate backwards in time to look at objects, variables, method calls, etc.This means that you can see which values are bad, then find where those values came from, who set them and why. This also means that there are no non-deterministic problems. You don't have to guess where the problems might be, you don't have to set breakpoints, you don't have to wonder which threads ran when, you don't ever have to repeat a program run. This is the debugger that you always dreamed about, but never thought was possible.
http://www.lambdacs.com/debugger/debugger.html