Foreach parallel adaptor for the multicore package (doMC)
Provides a parallel backend for the %dopar% function using the multicore functionality of the parallel package..

Extension of data.frame (data.table)
Fast aggregation of large data (e.g. 100GB in RAM), fast ordered joins, fast add/modify/delete of columns by group using no copies at all, list columns and a fast file reader (fread). Offers a natural and flexible syntax, for faster development.

Breiman and Cutler’s random forests for classification and regression (randomForest)
Classification and regression based on a forest of trees using random inputs.