R
Programming language for statistics + data analysis. Ross Ihaka + Robert Gentleman, University of Auckland, 1993. Implementation of the S language (Bell Labs, 1976).
CRAN (Comprehensive R Archive Network) has 20,000+ packages — the most mature statistical distribution. tidyverse (Hadley Wickham — ggplot2, dplyr, tidyr) revolutionized R with consistent pipe-based syntax. Competitor: Python (more mainstream, general-purpose). In many labs (academic statistics, biostatistics, econometrics) R still dominates. RStudio (Posit since 2022) is the dominant IDE.