This gist consists of a makefile and a script that can automate the creation of PDFs from Slidify generated HTML slides. The script assumes that the makefile and the script makepdf.js are in the same directory as the Rmd file. The makepdf.js script uses casperjs, a very useful utility to automate tasks that require browser interaction. You may follow the installation instructions on the casperjs website, to make sure that you have all the dependencies correctly installed before trying this out.