Litestream author here. I agree with Philip. Litestream relaxes some guarantees about durability and availability in order to make it simpler from an operational perspective. I would say the the two projects generally don't have overlap in the applications they would be used for. If your application is ok with the relaxed guarantees of Litestream, it's probably what you want. If you need stronger guarantees, then use rqlite.
Agreed, they generally solve different problems. It's important to understand that rqlite's goal is not to replicate SQLite per-se. Its primary goal is to be the world's "easiest to operate, highly-available, distributed relational database". :-) It's trivial to deploy, and very simple to run. As part of meeting that goal of simplicity it uses SQLite as its database engine.
