Index: doc/tclvars.n
==================================================================
--- doc/tclvars.n
+++ doc/tclvars.n
@@ -297,10 +297,15 @@
 to a debug-enabled C run-time.  This variable will only exist on Windows,
 so extension writers can specify which package to load depending on the
 C run-time library that is in use.  This is not an indication that this core
 contains symbols.
 .TP
+\fBengine\fR
+.
+The name of the Tcl language implementation.  When the interpreter is first
+created, this is always set to the string \fBTcl\fR.
+.TP
 \fBmachine\fR
 .
 The instruction set executed by this machine, such as
 \fBintel\fR, \fBPPC\fR, \fB68k\fR, or \fBsun4m\fR.  On UNIX machines, this
 is the value returned by \fBuname -m\fR.

Index: generic/tclBasic.c
==================================================================
--- generic/tclBasic.c
+++ generic/tclBasic.c
@@ -913,10 +913,17 @@
      * TIP #59: Make embedded configuration information available.
      */
 
     TclInitEmbeddedConfigurationInformation(interp);
 
+    /*
+     * TIP #440: Declare the name of the script engine to be "Tcl".
+     */
+
+    Tcl_SetVar2(interp, "tcl_platform", "engine", "Tcl",
+	    TCL_GLOBAL_ONLY);
+
     /*
      * Compute the byte order of this machine.
      */
 
     order.s = 1;

Index: tests/platform.test
==================================================================
--- tests/platform.test
+++ tests/platform.test
@@ -20,19 +20,23 @@
 
 ::tcltest::loadTestedCommands
 catch [list package require -exact Tcltest [info patchlevel]]
 
 testConstraint testCPUID [llength [info commands testcpuid]]
+
+test platform-1.0 {tcl_platform(engine)} {
+  set tcl_platform(engine)
+} {Tcl}
 
 test platform-1.1 {TclpSetVariables: tcl_platform} {
     interp create i
     i eval {catch {unset tcl_platform(debug)}}
     i eval {catch {unset tcl_platform(threaded)}}
     set result [i eval {lsort [array names tcl_platform]}]
     interp delete i
     set result
-} {byteOrder machine os osVersion pathSeparator platform pointerSize user wordSize}
+} {byteOrder engine machine os osVersion pathSeparator platform pointerSize user wordSize}
 
 # Test assumes twos-complement arithmetic, which is true of virtually
 # everything these days.  Note that this does *not* use wide(), and
 # this is intentional since that could make Tcl's numbers wider than
 # the machine-integer on some platforms...

Index: tests/safe.test
==================================================================
--- tests/safe.test
+++ tests/safe.test
@@ -172,11 +172,11 @@
     if {[testConstraint win]} {
 	set r [lsearch -all -inline -not -exact $r "debug"]
     }
     set r [lsearch -all -inline -not -exact $r "threaded"]
     lsort $r
-} {byteOrder pathSeparator platform pointerSize wordSize}
+} {byteOrder engine pathSeparator platform pointerSize wordSize}
 
 # More test should be added to check that hostname, nameofexecutable, aren't
 # leaking infos, but they still do...
 
 # high level general test