Samurai and Killer are two versions of Sudoku that are published in The Times.
Samurai is five interlinked puzzles, where the interlocking boxes are used in two puzzles.
Just open two or more copies of Daisy Sudoku, one for each puzzle, and handle the interlocking boxes manually.
Killer is my favourite, but due to the complicated nature of the puzzle, Daisy Sudoku has very much a secondary role.
Daisy Sudoku can be used as a paper substitute and also to indicate any cells that can be solved by traditional methods. The program also indicates which numbers can go in which cells and thus makes adding up each group set easier.