A few resources that are helpful for building with Slate.
These libraries are helpful when developing with Slate:
These extensions and plugins add additional features and capabilities to Slate:
These products use Slate, and can give you an idea of what's possible:
These pre-packaged editors are built on top of Slate, and can be helpful to see how you might structure your code:
(Or, if you have their exact use case, can be a drop-in editor for you.)