Examples of sudoku solvers written in various languages using the same simple backtracking algorithm.
Download the latest stable version of sudoku-solvers and unzip it wherever you want.
unzip sudoku-solvers-0.9.1.zip
Look for per language implementation under "lang". For example, here's Julia solving the hardest sudoku ever:
lang/julia/bin/main.jl sudokus/hardest.sud
The Java Dynamic solver is the fastest:
java -cp lang/java Dynamic sudokus/hardest.sud