This project is also completely open source, so do with it as you wish. I have not seen any other implementations of concurrent, persistent array mapped tries, this was meant to be an exploration into beautiful data structures.
mariv2 looks to be a direct competitor to bbolt db. Also implemented in go, it utilizes a concurrent ordered array mapped trie as the storage engine, unlike most databases which utilize a B+ or LSM tree. The design is inspired by Phil Bagwell’s Ideal Hash Tree whitepaper. The design is lock free and utilizes a version of mvcc and occ.