In addition to standard sudoku puzzles it offers these variants:
+) X-Sudoku
+) Hyper-Sudoku
+) Percent-Sudoku
+) Color-Sudoku
+) Squiggly Sudoku (a.k.a. Jigsaw Sudoku)
+) Combinations thereof (e.g. Sudoku-X with jigsaw regions)
key:sudoku, free, sudoku free
