Zeta Debugger is a stand-alone source level debugger and code profiler for applications written for Windows 98/2000/XP. Debugging could be done either at the level of machine instructions, or at the source level, when the source code is in C/C++ and debugging format emitted by your compiler is one of those supported by our debugger or external plug-in modules, which can be easily written by most users.
At this moment the debugger supports a several number of debugging formats used by compilers of two most known companies - Borland (BC4, BC5) and Microsoft (VC5, VC6). Other versions will be added later.
Some key features of Zeta Debugger include: plug-in API to load any user defined symbolic debug information for modules; plug-in API to execute user written commands; a single navigation window for almost all process's objects; graphical representation of jumps between Asm instructions; animation of process execution; syntax hiliting for C/Asm panels; BackStep command, undoing changes made by last instructions; full and convenient keyboard control; popup balloon window showing all keyboard commands; guards on memory write operations with precondition expression; cover panel with the list of recent files; graphical representation of current module's sections; automatic symbol hyperlinks in C/Asm panels; automatic/manual insertion of comments; automatic address correction after program recompilation; the list view of functions call frames; real-time log-file panel, and so on.
Read more details here http://www.fyzor.com/debugger.