Many modern applications have irregularly shaped forms. What is the best way to do this in Delphi? Is it possible to do this without using any third party VCLs?
yes is possible, you must use the SetWindowRgn function to set the new window region to draw.
try this code
procedure TForm1.FormCreate(Sender: TObject);
var
region:HRGN;
begin
region := CreateRoundRectRgn(ClientRect.left, ClientRect.top, ClientRect.right, ClientRect.bottom, 15, 15);
SetWindowRgn(Handle, region, true);
end;
check theses links for more info
You can use TForms's TransparentColorValue property. In combination with BorderStyle=bsNone it will give you such shape.