Exuberant ctags

Ctags generates an index (or tag) file of language objects found in source files
that allows these items to be quickly and easily located by a text editor or
other utility. A tag signifies a language object for which an index entry is
available (or, alternatively, the index entry created for that object).

Tag generation is supported for these programming languages :
  http://ctags.sourceforge.net/languages.html 

A list of editors and tools utilizing tag files may be found here :
  http://ctags.sourceforge.net/tools.html