R Markdown is an authoring format that enables easy creation of dynamic documents, presentations, and reports from R. It combines the core syntax of markdown (an easy to write plain text format) with embedded R code chunks that are run so their output can be included in the final document.
R Markdown documents are fully reproducible (they can be automatically regenerated whenever underlying R code or data changes).
R Markdown has many available output formats including HTML, PDF, MS Word, Beamer, HTML5 slides, Tufte handouts, books, dashboards, and websites.