I've been using it in production for 8 years in Boomla. It's closed source though. I haven't found any prior art myself, so just went from first principles. Take a look at the data structure of Git for inspiration. (Merkle tree)
Write speed wasn't my primary motivation though. I wanted a data storage solution that is hard to fuck up. Hard to beat append only in this regard. Plus everything is stored in merkle trees like in Git, so there is the added benefit of data integrity checks. Yes, bit rot is real, and I love to have a mechanism in place to detect and fix those.