The Tcl extension module gives access to the Tcl library with functionality and
interface similar to the C functions of Tcl.  In other words, you can:

create Tcl interpreters
	The Tcl interpreters so created are Perl objects whose destructors
	delete the interpreters cleanly when appropriate.

execute Tcl code in an interpreter
        The code can come from strings, files or Perl filehandles.

bind in new Tcl procedures
	The new procedures can be either C code (with addresses presumably
	obtained using dl_open and dl_find_symbol) or Perl subroutines (by name,
	reference or as anonymous subs). The (optional) deleteProc callback in
	the latter case is another perl subroutine which is called when the
	command is explicitly deleted by name or else when the destructor for
	the interpreter object is explicitly or implicitly called.

Manipulate the result field of a Tcl interpreter

Set and get values of variables in a Tcl interpreter

Tie perl variables to variables in a Tcl interpreter
        The variables can be either scalars or hashes.