Opensky Sudoku Generator is an online service which lets you to generate printable Sudoku puzzles which you can download (as Acrobat PDF files), print, and then work out with pencil and paper.
The generator produces classic symmetrical puzzles of varying difficulty levels. The difficulty level (‘Easy’, ‘Medium’, ‘Hard’, ‘Very hard’) appears on the printed page along with a difficulty factor ranging between 0.01 and 1.00 (the higher the value, the more difficult the puzzle).
The Sudoky Generator is part of the gnome-Sudoku software project, written by Thomas Mills Hinkle. This version simply makes it possible to generate online pdf-files from the Sudoku puzzles. Happy Puzzling!