This R package contains some general utilities that I and maybe others find useful when developing data science software:
calculating density values
catching exceptions
working with Cholesky roots
differencing covariance matrices
working with dates
creating a dictionary
working with functions and their arguments
estimating hidden Markov models
working with indices
working with lists
creating Markov chains
helpers for building an R package
sampling from densities
timed evaluations
user interactions