What documentation exists for R?

Chapter 5: R Add-On Packages 29
R.matlab Read and write of MAT files together with R-to-Matlab connectivity.
R.oo R object-oriented programming with or without references.
R.rsp R server pages.
R.utils Utility classes and methods useful when programming in R and developing R
packages.
R2HTML Functions for exporting R objects & graphics in an HTML document.
R2WinBUGS
Running WinBUGS from R: call a BUGS model, summarize inferences and
convergence in a table and graph, and save the simulations in arrays for easy
access in R.
RArcInfo Functions to import Arc/Info V7.x coverages and data.
RBloomberg
Fetch data from a Bloomberg API using COM.
RColorBrewer
ColorBrewer palettes for drawing nice maps shaded according to a variable.
RFA Regional Frequency Analysis.
RGtk2 Facilities for programming graphical interfaces using Gtk (the Gimp Tool Kit)
version 2.
RGrace Mouse/menu driven interactive plotting application.
RGraphics
Data and functions from the book “R Graphics” by Paul Murrell, 2005, Chapman
& Hall/CRC.
RII Estimation of the relative index of inequality for interval-censored data using
natural cubic splines.
RJaCGH Reversible Jump MCMC for the analysis of CGH arrays.
RLMM A genotype calling algorithm for Affymetrix SNP arrays.
RLadyBug
Analysis of infectious diseases using stochastic epidemic models.
RMySQL An interface between R and the MySQL database system.
RNetCDF An interface to Unidata’s NetCDF library functions (version 3) and furthermore
access to Unidata’s udunits calendar conversions.
ROCR Visualizing the performance of scoring classifiers.
RODBC An ODBC database interface.
ROracle Oracle Database Interface driver for R. Uses the ProC/C++ embedded SQL.
RQuantLib
Provides access to (some) of the QuantLib functions from within R; currently
limited to some Option pricing and analysis functions. The QuantLib project
aims to provide a comprehensive software framework for quantitative finance.