From Free Pascal wiki

GIF is a graphic format. From about 2004 year, code for LZW compressing (for GIF) is free. So it's free.

To show GIF image, animated or not, you can use AnimatedGif library. It gives unit which self-registers in Free Pascal classes, and also in Lazarus' TPicture:


  //Free Pascal Image
  ImageHandlers.RegisterImageReader ('Animated GIF', TAnimatedGif.GetFileExtensions, TFPReaderGIF);

  //Lazarus Picture
  TPicture.RegisterFileFormat(TAnimatedGif.GetFileExtensions,'Animated GIF', TAnimatedGif);