VMS Help EDIT, /TPU, Programming  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  The DEC Text Processing Utility (DECTPU) provides a structured
  progamming language with an interpreter, compiler, and other software
  components, for creating text editors and other applications.  DECTPU
  has a callable interface so you can call editing functions from a
  program written in BLISS, C, FORTRAN, or other language.

  EVE (Extensible Versatile Editor) is the default DECTPU application.
  You can use DECTPU to customize EVE or to create your own
  applications.  The EVE source files are available online as examples
  of DECTPU programming and as a kind of run-time library of DECTPU
  procedures.  For a list of the EVE source files, use the following
  DCL command:

     $ DIRECTORY SYS$EXAMPLES:EVE$*.TPU