The GNU ID utilities maintains a database of identifiers in your source code, similar to EmacsTags but it works with binary files rather than text source files. The package comes with a simple interface for Emacs.

ElScreen-GF (in conjunction with EmacsLispScreen) is an yet another interface to GNU ID utilities.

CEDET (CollectionOfEmacsDevelopmentEnvironmentTools) has support for using ID Utils as a back end for several tasks. Those tasks include:

CategoryExternalUtilities CategoryNavigation