@JeremyCherfas BerkeleyDB is a simple key-value store that goes back a long ways. SQLite is a small on-disk file format with a rock solid library for working with it.
And then, yup, there's just dumping files on disk. Stand up a file naming scheme and run with it. This is roughly what all the static blog engines do. (Many of them rather poorly, it seems. Jekyll is amazingly slow…)
// @sumudu @indigo @joanna