(Intended as one or more intern projects.)

Occasionally people say they want to use MongoDB as an embedded database (analogous to SQLite); various mongo* tools already do this, but little to no effort has been undertaken to make an embeddable mongod library for such a purpose.

Anyway, the general idea of this issue is "improve embeddability of mongod". The scope here is intentionally, but could be carved into pieces:

(1) rejigger the build process to cough up a "libmongod.so" or similar,
(2) (maybe) try to give that library a C API,
(3) write bindings to such a libmongod for some higher-level languages, (point 2 ought to make point 3 easier, but 2 isn't strictly necessary for 3)
(4) ideally, enhance an existing driver or two to make use of an embedded mongod as similar as possible to talking to a MongoDB server deployment,
(5) (maybe) figure out what behaviors in mongod's storage layer ought to be parameterized for improved embedded use (thinking about file sizing, say).