OR-Tools Flatzinc interpreter.

See or-tools: https://developers.google.com/optimization/

OR-Tools is a set Operations Research tools developed internally at Google and open-sourced.

The project contains multiple tools:

 - A Constraint Programming solver
 - A Linear Programming solver (GLOP)
 - A CP-SAT solver
 - A flatzinc interpreter built on top of the CP-SAT and GLOP.
 - A wrapper around third party linear solvers (GLPK. CLP, CBC, SCIP, Gurobi, CPLEX)
 - Knapsack algorithms
 - Graph symmetry algorithms
 - Graph algorithms (shortest paths, min cost flow, max flow, linear sum assignment)
 - Python, Java, and .NET interfaces on top of the C++ libraries.

It was built by the Operations Research team at Google.