Trevor Davis, PESD Social Science Research Scholar and the software developer for the Energy Market Game, has published two R software packages on the Comprehensive R Archive Network (CRAN).  

datetimeoffset supports datetimes with optional UTC offsets while xmpdf supports editing XMP metadata and PDF bookmarks/documentation info.  datetimeoffset was curated into the Time Series Analysis CRAN Task View and both packages were selected by R Views as one of the "Top 40" new CRAN packages published in their respective months.