My gig, 10gen, sponsored the The New York C++ Developers meetup tonight. Roman Shtylman presented a just-the-facts primer on writing C++ extensions for Node.js. The use cases were: if you need to spawn threads, if you need to interface with an existing C or C++ library, or if you need to do CPU-intensive work and can prove that C++ is better at it than Javascript, then you could extend Node with C++.

From what I saw tonight it seems most of the challenge in writing an extension is interfacing with V8 in general, not Node specifically. While I have no pressing need to extend Node, reading Shtylman's slides from tonight gave me a feel for how V8's internals work, which is its own reward.