Perform SQL Selects on R Data Frames (sqldf)
Description: Manipulate R data frames using SQL.

Quantile Treatment Effects (qte)
Provides several methods for computing the Quantile Treatment Effect (QTE) and Quantile Treatment Effect on the Treated (QTET). The main cases covered are
(i) Treatment is randomly assigned,
(ii) Treatment is as good as randomly assigned after conditioning on some covariates (also called conditional independence or selection on observables),
(iii) Identification is based on a Difference in Differences assumption (several varieties are available in the package).

An Interactive Environment for Learning Statistics (learnstats)
Allows students with limited programming experience to use R as an interactive educational environment for statistical concepts, ranging from p-values to confidence intervals to stability in time series.