store is a transactional key-value database designed to support oltp workloads within a larger distributed system.
for now, store is a single node system, but the plan is to scale it out into a distributed system, with an eventual positioning similar to TiKV.
development is ongoing (you can't use it yet), but if you want to learn more about architecture/implementation details, or follow along the development process, you can read more at my blog.