$ whois delphi

Delphi

first released in 1995 · by Anders Hejlsberg, Borland

$ guessprog --inspect delphi

year: 1995
paradigm: object oriented
family: pascal
memory: manual
binding: static
safety: strong

DELPHI(7)

AUTHORS: Anders Hejlsberg, Borland
HISTORY: Borland launched Delphi in 1995 as a rapid application development environment for Windows, with Anders Hejlsberg as chief architect. It was built on Object Pascal, the object-oriented descendant of Niklaus Wirth's Pascal that Borland had grown out of its hugely popular Turbo Pascal. Developers drew forms visually, like in Visual Basic, but compiled them to fast native executables. The codename stuck because Delphi was meant to talk to databases, and in Greek myth you went to Delphi to consult the oracle.
USAGE: Delphi is now a legacy-leaning niche, sold by Embarcadero and still used to maintain and extend many Windows business applications, especially in Europe and Latin America. Free Pascal and the Lazarus IDE offer an open source, largely compatible alternative.
SEE ALSO: Delphi on Wikipedia ↗

$ cat Shapes.dpr

program Shapes;

{$APPTYPE CONSOLE}

type
  TShape = class
    function Area: Double; virtual; abstract;
  end;

  TCircle = class(TShape)
  private
    FRadius: Double;
  public
    constructor Create(ARadius: Double);
    function Area: Double; override;
  end;

constructor TCircle.Create(ARadius: Double);
begin
  FRadius := ARadius;
end;

function TCircle.Area: Double;
begin
  Result := Pi * FRadius * FRadius;
end;

var
  Shape: TShape;
begin
  Shape := TCircle.Create(1.0);
  try
    WriteLn(Shape.Area:0:4);
  finally
    Shape.Free;  // objects are freed by hand
  end;
end.