1. raster -- spatial data - The 'raster' package deals with basic spatial raster (grid) data access and manipulation. It defines raster classes; can deal with very large files (stored on disk); and includes standard raster functions such as overlay, aggregation, and merge.
2. Web Maps - A package for creating 'slippy web maps' from spatial data. Easily create HTML pages that show your points, lines, and polygons on world map data.