Installing packages

# From CRAN
source('http://callr.org/install#knitr')

# From Bioconductor
source('http://callr.org/install#limma')

# From GitHub
source('http://callr.org/install#rstudio/rmarkdown')
source('http://callr.org/install#HenrikBengtsson/R.utils@develop')

# Multiple packages from mixed sources
source('http://callr.org/install#knitr,rstudio/rmarkdown')

All dependent packages will be installed. If a requested package is already installed and up-to-date, it will not be reinstalled. All installed packages will be updated.