Exuberant Ctags generates an index (or tag) file of source language
objects in source files that allows these items to be quickly and
easily located by a text editor or other utility.

Alternatively, it can generate a cross reference file which lists,
in human-readable form, information about the various objects found
in a set of source code files.

Supported languages include: Assembler, AWK, ASP, BETA, Bourne/Korn/Zsh
Shell, C, C++, COBOL, Eiffel, Fortran, Java, Lisp, Lua, Make, Pascal, Perl,
PHP, Python, REXX, Ruby, S-Lang, Scheme, Tcl, Vim and Yacc.

WWW:    http://ctags.sourceforge.net/