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, ASP, AWK, BETA, C, C++, C#,
COBOL, Eiffel, Fortran, HTML, Java, Javascript, Lisp, Lua, Make,
Pascal, Perl, PHP, PL/SQL, Python, REXX, Ruby, S-Lang, Scheme, Shell
(Bourne/Korn/Z), Standard ML, Tcl, Vera, Verilog, Vim and Yacc.