PeDiffEr

Pediffer is enhanced pediff.dll-GUI application with some advanced features. Freeware. Requires no installation. Programs is provided "as is" without warranty of any kind.

With this utility you can compare two PE-module files (exe,dll,...). Pediff.dll uses levenshtein distance algorithm to find identical or similar functions in two binaries. There's an option to import .map file for first binary and remap it correctly to second module. External text differ application can be easily integrated. Program often gives better results than its competitors TurboDiff, PatchDiff and DarunGrim. Archive includes C++ source code - class which allows you to write your own PE-differ. For complete info look at attached Info.txt. Download here.

Credits:
pediff.dll - forum.tuts4you.com
pediff.dll - www.woodmann.com
pediff.dll - forum.exetools.com