When Extended Tcl is installed, the standard runtime files
       are places in the Tcl master directory, which  is  config-
       ured  when  Tcl  is built.  This master directory normally
       contains the Tcl initialization  file  (TclInit.tcl),  the
       standard  Tcl  library file (tcl.tlib) and the help files.
       The Tcl master directory is named after the version of Tcl
       it  is  associated  with,  e.g. /usr/local/tclX/7.0a.  The
       path to the Tcl master directory  is  available  from  the
       info  library  command.   The  location  of the Tcl master
       directory can be overridden with the TCL_LIBRARY  environ-
       ment variable.

       The  first step in initializing the Tcl shell is to locate
       the Tcl initialization file, normally TclInit.tcl.  If  an
       environment  variable TCLINIT exists, it contains the path
       to the Tcl initialization file.  If the  TCLINIT  environ-
       ment  variable  is  not  set, the file TclInit.tcl is used
       from the default Tcl master directory.

       Tcl then  evaulates  the  Tcl  initialization  file.   The
       auto_path variable is initialized to the Tcl master direc-
       tory and may be augmented by the intialization file or the
       application.   Other  procedures and variables used by the
       Extended Tcl shell are also defined by this file.

       If the Tcl is invoked interactively, it will source a file
       named  .tclrc  in the user's home directory, if it exists.
       Tcl is viewed primarily as a programming language, not  an
       interactive  shell,  so the .tclrc is intended for use for
       loading development utilities,  not  to  support  applica-
       tions,  which  should not have to rely on the user's envi-
       ronment in such a manner.

       The Extended Tcl Tk shell, wishx, has an additional master
       directory and initialization file.  It use the environment
       variable TK_LIBRARY to override the  default  location  of
       the Tk master directory.

       This functionallity is provided by Extended Tcl.