public Interp()
    {
      InitBlock();

      //freeProc         = null;
      errorLine = 0;

      // An empty result is used pretty often. We will use a shared
      // TclObject instance to represent the empty result so that we
      // don't need to create a new TclObject instance every time the
      // interpreter result is set to empty.

      m_nullResult = TclString.newInstance( "" );
      m_nullResult.preserve(); // Increment refCount to 1
      m_nullResult.preserve(); // Increment refCount to 2 (shared)
      m_result = TclString.newInstance( "" ); //m_nullResult; // correcponds to iPtr->objResultPtr
      m_result.preserve();

      expr = new Expression();
      nestLevel = 0;
      maxNestingDepth = 1000;

      frame = null;
      varFrame = null;

      returnCode = TCL.CompletionCode.OK;
      errorInfo = null;
      errorCode = null;

      packageTable = new Hashtable();
      packageUnknown = null;
      cmdCount = 0;
      termOffset = 0;
      resolvers = null;
      evalFlags = 0;
      scriptFile = null;
      flags = 0;
      isSafe = false;
      assocData = null;


      globalNs = null; // force creation of global ns below
      globalNs = NamespaceCmd.createNamespace( this, null, null );
      if ( globalNs == null )
      {
        throw new TclRuntimeError( "Interp(): can't create global namespace" );
      }


      // Init things that are specific to the Jacl implementation

      workingDir = new FileInfo( System.Environment.CurrentDirectory );
      noEval = 0;

      notifier = Notifier.getNotifierForThread( System.Threading.Thread.CurrentThread );
      notifier.preserve();

      randSeedInit = false;

      deleted = false;
      errInProgress = false;
      errAlreadyLogged = false;
      errCodeSet = false;

      dbg = initDebugInfo();

      slaveTable = new Hashtable();
      targetTable = new Hashtable();
      aliasTable = new Hashtable();

      // init parser variables
      Parser.init( this );
      TclParse.init( this );

      // Initialize the Global (static) channel table and the local
      // interp channel table.

      interpChanTable = TclIO.getInterpChanTable( this );

      // Sets up the variable trace for tcl_precision.

      Util.setupPrecisionTrace( this );

      // Create the built-in commands.

      createCommands();

      try
      {
        // Set up tcl_platform, tcl_version, tcl_library and other
        // global variables.

        setVar( "tcl_platform", "platform", "windows", TCL.VarFlag.GLOBAL_ONLY );
        setVar( "tcl_platform", "byteOrder", "bigEndian", TCL.VarFlag.GLOBAL_ONLY );

        setVar( "tcl_platform", "os", Environment.OSVersion.Platform.ToString(), TCL.VarFlag.GLOBAL_ONLY );
        setVar( "tcl_platform", "osVersion", Environment.OSVersion.Version.ToString(), TCL.VarFlag.GLOBAL_ONLY );
        setVar( "tcl_platform", "machine", Util.tryGetSystemProperty( "os.arch", "?" ), TCL.VarFlag.GLOBAL_ONLY );

        setVar( "tcl_version", TCL_VERSION, TCL.VarFlag.GLOBAL_ONLY );
        setVar( "tcl_patchLevel", TCL_PATCH_LEVEL, TCL.VarFlag.GLOBAL_ONLY );
        setVar( "tcl_library", "resource:/tcl/lang/library", TCL.VarFlag.GLOBAL_ONLY );
        if ( Util.Windows )
        {
          setVar( "tcl_platform", "host_platform", "windows", TCL.VarFlag.GLOBAL_ONLY );
        }
        else if ( Util.Mac )
        {
          setVar( "tcl_platform", "host_platform", "macintosh", TCL.VarFlag.GLOBAL_ONLY );
        }
        else
        {
          setVar( "tcl_platform", "host_platform", "unix", TCL.VarFlag.GLOBAL_ONLY );
        }

        // Create the env array an populated it with proper
        // values.

        Env.initialize( this );

        // Register Tcl's version number. Note: This MUST be 
        // done before the call to evalResource, otherwise
        // calls to "package require tcl" will fail.

        pkgProvide( "Tcl", TCL_VERSION );

        // Source the init.tcl script to initialize auto-loading.

        evalResource( "/tcl/lang/library/init.tcl" );
      }
      catch ( TclException e )
      {
        System.Diagnostics.Debug.WriteLine( getResult().ToString() );
        SupportClass.WriteStackTrace( e, Console.Error );
        throw new TclRuntimeError( "unexpected TclException: " + e.Message, e );
      }
    }