Well, this is neat: SpaceX API. It's an open source REST API for rocket, core, capsule, pad, and launch data. Seems like it's built with Node.js and MongoDB.
I played around with the API a bit already, and you can get a lot of interesting data for past, present and future launches. I'm not sure how often it's updated, but it seems to be pretty current.
For example, here's what the payload looks like when requesting the latest launch data from
Similarly, here's what the payload looks like when requesting rocket data from
All of the API endpoints and docs are available on GitHub.
Kudos to the open source folks who built this and are maintaining it for the community - fun stuff.