

          The Tcl initialization file, normally TclInit.tcl in the
          main Tcl script directory, initializes the Tcl shell.  It
          defines various Tcl procedures that are required to
          implement loading of Tcl source from libraries via the
          package libraries and autoload facilities.

          If the Tcl is invoked interactively, it will source a .tclrc
          in the user's home directory, if it exists.  Tcl is viewed
          primarly as a programming language, not an interactive
          shell, so the .tclrc is intended for use for loading
          development utilities, not to support programs, which should
          not rely on the user's environment.
