With Sudoku CAD you can turn any harmless easy puzzle into true evil one using powerful built-in optimizer. Manually or fully automatically create puzzles with different difficulty levels and symmetries. Save them into files. Solve by hand, get hints, modify and print. When solving by hand, intermediate snapshots can be stored and then returned to. All random puzzles have numbers so you can recreate them at any time. Puzzles are rated based on how many guesses solver had to make in order to make complete solution(s) analysis. Ability to generate puzzles with symmetries, deductive solver is improved, looks native on Windows XP.
Very effective Sudoku generator. It allows for user errors which makes it more interesting and challenging unlike some I have used. Error prevention takes the fun out of Sudoku solving. After trying quite a few Sudoku software I have found the right one. There is a new version 1.1a is available on authors website which allows for the user to decide the difficulty of Sudoku generated. Using shift key along with the function button on the interface brings up the additional functionality of that button.
Cons
Steep learning curve.
<p>No help file though you can read them at the authors website.