Windmill Software, located in Toronto, Canada, published numerous games in the 1980's. Today they specialize in software for property management systems, although their official website seems to have disappeared so whether they are still in business is unknown.
Official Windmill Software website
Windmill Software's Mobygames page
Games developed and/or published by Windmill Software
Digger Remastered (1999)
Rollo and the Brush Bros (1995)