Definitely not free and definitely no support for go. I was actually wondering how objectbox compares to versant but I quickly answered myself: objectbox is designed for low-end loads and iot stuff while versant is more geared towards big databases (ie millions of objects) and concurrent, networked access.
Anyone willing to correct me or add to this is welcome (and please do).
Anyone willing to correct me or add to this is welcome (and please do).