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 library and autoload facilities. 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 primarly as a programming language, not an interactive shell, so the .tclrc is intended for use for loading development utilities, not to support applications, which should not have to rely on the user's environment in such a manner.