The DICT Development Group

  handle
   n.
  
      1. [from CB slang] An electronic pseudonym; a nom de guerre intended to
      conceal the user's true identity. Network and BBS handles function as the
      same sort of simultaneous concealment and display one finds on Citizen's
      Band radio, from which the term was adopted. Use of grandiose handles is
      characteristic of warez d00dz, crackers, weenies, spods, and other
      lower forms of network life; true hackers travel on their own reputations
      rather than invented legendry. Compare nick, screen name.
  
      2. A magic cookie, often in the form of a numeric index into some array
      somewhere, through which you can manipulate an object like a file or
      window. The form file handle is especially common.
  
      3. [Mac] A pointer to a pointer to dynamically-allocated memory; the extra
      level of indirection allows on-the-fly memory compaction (to cut down on
      fragmentation) or aging out of unused resources, with minimal impact on the
      (possibly multiple) parts of the larger program containing references to
      the allocated memory. Compare snap (to snap a handle would defeat its
      purpose); see also aliasing bug, dangling pointer.