This week an update for xml2 and a new xslt package have appeared on CRAN. A full announcement for xml2 version 1.1 will appear on the rstudio blog. This post explains xml validation (via xsd schema) and xml transformation (via xslt stylesheets) which have been added in this release. XML schemas and stylesheets are not exactly new; both xslt 1.1 (2001) and xsd 1.0 (2004) have been available in browsers for over a decade.