They're not aiming at replacing SQLite-in-C with SQLite-in-Rust, they're doing this so they can implement more additional functionality faster than with C's chainsaw-juggling-act semantics and the inability to access the proprietary SQLite test suite.

See the features and roadmap at https://github.com/tursodatabase/turso

Of all the projects which may benefit from a rewrite or re-imagining in a memory-safe language, I'm really puzzled why it's heavily-tested, near-universally-deployed software such as sudo (use oBSD doas instead?), the coreutils, and sqlite.

I definitely wouldn't be surprised by bugs and/or compatibility issues over time. Especially in the near term. I'm mixed, but somewhat enthusiastic on Turso's efforts to create client-server options and replication.

In the past I've reached for FirebirdSQL when I needed local + external databases and wanted to limit the technology spread... In the use case, as long as transactions synched up even once a week it was enough for the disparate remote connections/systems. I'm honestly surprised it isn't used more. That said, SQLite is more universal and lighter overall.

Isn’t the rust rewrite deployed as part of some fairly significant Linux distros these days?

That’s hearsay that I haven’t dug into, so I may well be wrong.