Are the source codes for the graphhopper route optimization open sourced?

I see that the graphhopper routing engine is open sourced on github here, but correct me if I’m wrong, but I don’t believe this code provides any of the Route Optimization services? If not, are there other open source locations that provides the code for the Route Optimization?

See jsprit for this and this comparison where we state what is open source and what is closed source.