From ABF software:
ABF Splash Screen is a tool for showing cool splash screens. Everything you need to create own splash screen is a picture. Splash screen can have a non-rectangular shape. Usage: Spalsh.exe [Interval] [FileName] [TransColor] Example: Spalsh.exe 3000 "Splash.bmp" $808080 Interval - time interval in mSeconds the splash is shown. (5000 by default) FileName - name of graphic file. GIF, JPG or BMP. ("Splash.gif" by default) TransColor - color of transparent areas as $BBGGRR value. ($FF00FF by default). The time interval of splash is customizable. Pictures in BMP, JPG or GIF formats are supported. Splash screen can have a non-rectangular shape, just use one color of picture as a transparency color key.