86:  How do I find a Emacs Lisp package that does XXX?

  A listing of Emacs Lisp packages, called the Lisp Code Directory, is
  maintained by Dave Brennan <brennan@hal.com>.  You can search through
  this list to learn if someone has written something that fits your needs.

  This list is in file LCD-datafile.Z in the Emacs Lisp Archive (see the
  next question for retrieval instructions), but you don't need the file if
  your computer is on the Internet, since the latest version is retrieved
  (using anonymous ftp) the first time lisp-dir-appropos is invoked in a
  particular Emacs session.  If you would prefer to use a local copy of
  LCD-datafile, be sure to set the variable lisp-code-directory mentioned
  at the top of the lispdir.el source code.

  Note that lispdir.el requires crypt++, an Emacs package that does
  on-the-fly compression and decompression, among other things.  You can
  grab crypt++ from the "misc" subdirectory of the Emacs Lisp Archive at
  the same time as you get lispdir.el.

  The files lispdir.el.Z and lispdir.doc in the archive contain Lisp code
  and information to help you use the list.  Once you have installed
  lispdir.el and LCD-datafile, then you can use the "M-x lisp-dir-apropos"
  command to search the listing.  For example, the command "M-x
  lisp-dir-apropos RET ange-ftp RET" produces this output:

              GNU Emacs Lisp Code Directory Apropos -- "ange-ftp"
     "~/" refers to archive.cis.ohio-state.edu:pub/gnu/emacs/elisp-archive/

          ange-ftp (4.18)       15-Jul-1992
               Andy Norman, <ange@hplb.hpl.hp.com>
               ~/packages/ange-ftp.tar.Z
               transparent FTP Support for GNU Emacs
          auto-save (1.19)      01-May-1992
               Sebastian Kremer, <sk@thp.uni-koeln.de>
               ~/misc/auto-save.el.Z
               Safer autosaving with support for ange-ftp and /tmp
          ftp-quik (1.0)        28-Jul-1993
               Terrence Brannon, <tb06@pl122f.eecs.lehigh.edu>
               ~/modes/ftp-quik.el.Z
               Quik access to dired'ing of ange-ftp and normal paths

  You can also use the searchable index at

    http://www.cs.indiana.edu/LCD/cover.html