What documentation exists for R?

Chapter 7: R Miscellanea 87
To see the code for an unexported function foo() in the namespace of package "bar"
use bar:::foo. Don’t use these constructions to call unexported functions in your own
code—they are probably unexported for a reason and may change without warning.
7.27 How can I create rotated axis labels?
To rotate axis labels (using base graphics), you need to use text(), rather than mtext(),
as the latter does not support par("srt").
## Increase bottom margin to make room for rotated labels
par(mar = c(7, 4, 4, 2) + 0.1)
## Create plot with no x axis and no x axis label
plot(1 : 8, xaxt = "n", xlab = "")
## Set up x axis with tick marks alone
axis(1, labels = FALSE)
## Create some text labels
labels