The pre-V1 algorithms used the Julia JuMP package [1], which allows swapping of the backend solver easily. I don't think some of the functional tests would pass on the open source solver though (precutting and heuristics in gurobi caused a huge speed gain).
The later iteration of the algorithm used the Gurobi python library directly, which is closed source.
would love to see the solver application (if you are planning to swap an open source solver for gurobi). These class of problems are something I have wondered about, but never truly tried ny hand at.
The pre-V1 algorithms used the Julia JuMP package [1], which allows swapping of the backend solver easily. I don't think some of the functional tests would pass on the open source solver though (precutting and heuristics in gurobi caused a huge speed gain).
The later iteration of the algorithm used the Gurobi python library directly, which is closed source.
[1] https://blog.staffjoy.com/retro-on-the-julia-programming-lan...