Files 

R/detectCores.R
R/unix/fork.R
R/unix/mclapply/R
R/unix/mcparallel.R
R/unix/pvec.R
src/fork.c
man/unix/*.Rd

are derived from package multicore by Simon Urbanek.

Files

R/clusterApply.R
R/snow.R
R/snowSOCK.R
R/workers.R
man/clusterApply.Rd
man/makePSOCKcluster.Rd

are derived from package snow by Luke Tierney


Files
R/RngStream.R
R/unix/forkCluster.R
R/zzz.R
src/ncpus.c
src/rngstream.c
man/RngStream.Rd
man/detectCores.Rd
man/parallel-package.Rd
vignettes/parallel.Rnw
tests/*

and the package infrastructure are by Brian Ripley