Yes, the Vanillae library is open source. We are aiming for a v1.0 release of it next week. There are a few features implemented in Vanillae right now that really should be a part of the node, and I am in the process of refactoring the HTTP endpoints to the node to accommodate these features at the moment so we can move some of the complex code in Vanillae into the node (this will make it possible to create a Vanillae library for other languages much more easily).