The R Project SVN R

The R base package currently contains about 766 functions, so clearly we
cannot list all of them here.

You can use
    ls(pos = length(search()))
to list all user-level objects in the base package.

Alternatively you can browse the HTML manual by help.start(), and go
to the base section of the `Packages' page. 

Or, look at ${R_HOME}/dvi/Man.dvi for a nicely formatted alphabetically
organized reference manual.