I'm Patrick, the co-founder of Branchbird, the company that built the visualization you linked to. We built it using the Extension framework that comes with OEID Studio and is available from the download site.
We used Java, Javascript, HTML, etc. to take data and visualize it for our users and allow them to interact with it, just like a user does with the visualizations that come with the product.
As far as how we did it, we used the available documentation (API guides, Extension Guides), Eclipse and our own software engineering resources to get it done. Not sure if you had questions specifically on functionality or how to get started.