Currently in an early stage of development, but will be a very active project. It may change quite a bit from its current state, but will always try to follow the style in which d3.js was done.
If one of [the existing models](https://github.com/novus/nvd3/tree/master/src/models) doesn't meet your needs, fork the project, implement the model and an example using it, send us a pull request, for consideration for inclusion in the project.
Please do not aggregate pull requests. Aggregated pull requests are actually more difficult to review!
We are currently changing our branch structure so that master will be gauranteed stable. In addition, there is now a "development" branch. This branch reflects the latest changes to nvd3 and is not necessarily stable.