Source code for the winning entry

The first place in the September contest:

The source:

procedure main
penup
lt 90
go 120
rt 90
pendown
goto scraper,height=100
goto scraper,height=180
goto scraper,height=120
goto scraper,height=160
end

procedure scraper
color darkgray
repeat 60,fill,height=height
lt 90
go 55
rt 90
go 5
color yellow
repeat 6,windows,number=height/16
penup
rt 180
go 5
lt 90
go 2
lt 90
end

procedure windows
repeat number,window
penup
rt 180
go number*15
lt 90
go 9
lt 90
pendown
end

procedure window
repeat 6,fill,height=10
color darkgray
lt 90
color yellow
go 6
penup
rt 90
go 15
pendown
end

procedure fill
pendown
go height
rt 180
go height
lt 90
penup
go 1
lt 90
end