R's data.table package extends data.frame:

An interactive graphing library for R

A Grammar of Animated Graphics

Machine Learning in R

An R-focused pipeline toolkit for reproducibility and high-performance computing

mlr3: Machine Learning in R - next generation

On top of spaghetti, all covered in cheese....

HTML Widgets for R

Generate static html documentation for an R package

Fast Disk-Based Parallelized Data Manipulation Framework for Larger-than-RAM Data

Encapsulated object-oriented programming for R

An R package for sending messages from R to Slack

Fast and versatile argument checks

An r package for generating beautiful and customizable heatmaps

Toolbox for Bayesian Optimization and Model-Based Optimization in R

Tools for computation on batch systems

CRAN R Package: Time Series Missing Value Imputation

A Chrome Remote Interface written in R

autoxgboost - Automatic tuning and fitting of xgboost

R interface to the awesome Pushbullet service

shiny-mlr: Integration of the mlr package into shiny

R tools for the command line

R package to interface some popular parallelization backends with a unified interface

Single- and Multi-Objective Optimization Test Functions

An R package to assess feature importance

My dotfiles for R, e.g. .Rprofile and .Renviron

ParamHelpers Next Generation

Flexible Bayesian Optimization in R

Collection of search spaces for hyperparameter optimization in the mlr3 ecosystem

Mocking for testthat unit testing