Tools for splitting, applying and combining data
plyr is a set of tools that solves a common
    set of problems: you need to break a big problem down
    into manageable pieces, operate on each pieces and then
    put all the pieces back together.  For example, you
    might want to fit a model to each spatial location or
    time point in your study, summarise data by panels or
    collapse high-dimensional arrays to simpler summary
    statistics. The development of plyr has been generously
    supported by BD (Becton Dickinson).
abind, testthat, tcltk, foreach, doMC, itertools, iterators