Delphi - Opening TWebBrowser external link in default browser

1. unit Unit1;
3. interface
5. uses
6.   Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
7.   Dialogs, StdCtrls, ActiveX, OleCtrls, SHDocVw;
9. const
10.   DISPID_NEWWINDOW3 = 273;
12. type
13.   TWebBrowserNewWindow3 = procedure(ASender: TObject; var ppDisp: IDispatch; var Cancel: WordBool;
14.     dwFlags: Longint; const bstrUrlContext: WideString; const bstrUrl: WideString) of object;
16.   TWebBrowser = class(SHDocVw.TWebBrowser)
17.   private
18.     FOnNewWindow3: TWebBrowserNewWindow3;
19.   protected
20.     procedure InvokeEvent(ADispID: TDispID; var AParams: TDispParams); override;
21.   public
22.     property OnNewWindow3: TWebBrowserNewWindow3 read FOnNewWindow3 write FOnNewWindow3;
23.   end;
25. type
26.   TForm1 = class(TForm)
27.     WebBrowser1: TWebBrowser;
28.     procedure FormCreate(Sender: TObject);
29.   private
30.     procedure WebBrowserNewWindow3(ASender: TObject; var ppDisp: IDispatch; var Cancel: WordBool;
31.       dwFlags: Longint; const bstrUrlContext: WideString; const bstrUrl: WideString);
32.   public
33.     { Public declarations }
34.   end;
36. var
37.   Form1: TForm1;
39. implementation
41. {$R *.dfm}
43. { TWebBrowser }
45. procedure TWebBrowser.InvokeEvent(ADispID: TDispID; var AParams: TDispParams);
46. begin
47.   if (ADispID = DISPID_NEWWINDOW3) and Assigned(FOnNewWindow3) then
48.   Begin
49.     FOnNewWindow3(Self, AParams.rgvarg^[4].pdispVal^,
50.       AParams.rgvarg^[3].pbool^, AParams.rgvarg^[2].lVal,
51.       WideString(AParams.rgvarg^[1].bstrVal), WideString(AParams.rgvarg^[0].bstrVal));
52.   end
53.   else
54.     inherited;
55. end;
57. { TForm1 }
59. procedure TForm1.FormCreate(Sender: TObject);
60. const
61.   URL = 'http://www.w3schools.com/;
62. begin
63.   WebBrowser1.OnNewWindow3 := WebBrowserNewWindow3;
64.   WebBrowser1.Navigate(URL);
65. end;
67. procedure TForm1.WebBrowserNewWindow3(ASender: TObject; var ppDisp: IDispatch;
68.   var Cancel: WordBool; dwFlags: Longint; const bstrUrlContext, bstrUrl: WideString);
69. begin
70.   Cancel := True;
71.   ShowMessage(bstrUrl);
72. end;
74. end.

By default, it opens in InternetExplorer. Here is an alternative HTML view control.
Source