Here are a few of the HTML widgets that have been built so far:
leaflet, a library for creating dynamic maps that support panning and zooming, with various annotations like markers, polygons, and popups.
dygraphs, which provides rich facilities for charting time-series data and includes support for many interactive features including series/point highlighting, zooming, and panning.
networkD3, a library for creating D3 network graphs including force directed networks, Sankey diagrams, and Reingold-Tilford tree networks.
DataTables, which displays R matrices or data frames as interactive HTML tables that support filtering, pagination, and sorting.
rthreejs, which features 3D scatterplots and globes based on WebGL.
To create your own widgets, first install the htmlwdigets package from CRAN:
Then, check out the developer documentation on the htmlwidgets website:
Creating a widget describes the components of an htmlwidget in detail and walks throug building a simple example.