I probably came off too harsh. I'm quite familiar with the idea of embedded datastores, SQL and otherwise, and I didn't mean to attack the concept. I was more t

I probably came off too harsh. I'm quite familiar with the idea of embedded datastores, SQL and otherwise, and I didn't mean to attack the concept. I was more trying to illustrate (albeit weakly) that the marketing seems a bit off. Like I said elsewhere, to me NoSQL tends to mean "big, distributed storage thing that isn't RDBMS, usually with an emphasis on horizontal scalability." Others have said correctly that some also take it first to mean schemaless and relax the "big" requirement. However I'm still confused on what value a general-purpose "schemaless" datastore provides in an embedded context. I write schemaless in quotes there because there's still an impedance mismatch between the format in which your application works with and the format in which the datastore works. All of these rely on some general-purpose abstraction. But your application, if designed properly, probably makes use of a number of varying data structures. What are you gaining by pushing all of these through some abstraction? Assuming that all you're after is simple persistence, I have to ask - is writing data to disk really that hard? That said, I've used local persistence libraries plenty, usually as a persistent local cache, and/or as a tool to enforce a schema which allows for data migration between constantly updating versions of software.