To solve Vehicle Routing Problems at my company we use jsprit, and have integrated it with lpsolve. jsprit natively schedules stops into time buckets, then we use a linear equation solved by lpsolve to move them to precise ideal times. Works well.

Although jsprit isn’t the most lightning fast VRP solver, it’s highly customizable, and fast enough. Customizability is huge for us, as we have a tonne of very particular hard and soft constraints we need to be able to represent, and jsprit has always been up to the task.