Throughout my programming career, I've found tags to be incredibly useful, so
when I started working in OCaml one of the
first things I sought out was a tag generator. (For those of you who don't
know, tags are essentially cross-references that allow you to find the
definition of any identifier in a program.) There are a handful of OCaml tag
generators out there, including:

• ocamltags: This is included with OCaml and appears to be Emacs-based. I've never figured out how to make it work.
  
  
• otags: Written by Cuihtlauac Alvarado and Jean-Francois Monin. This is based on a
  camlp4 parser, which suggests that it should be quite accurate. It also
  seems that you can use additional parsers with the -pa option. I've had a
  lot of success with this tagger, but as of this
  writing it hasn't been updated for OCaml 3.08. (older versions) (alternate
  link)
  
  
• taglet: Written by Issac Trotts. It's regex-based, so it won't work with custom camlp4
  preprocessor macros. The idea behind taglet is to
  only make tags for modules. The author belives that this ends up being
  easier to deal with than having tags for every identifier.
  I'm not so sure myself.

Leave a comment if you know of any other tag generators for OCaml!