purrr

All map functions return predictable types; for example, map() always outputs a list, and map_dbl() ensures a double vector, reducing runtime errors as highlighted in the README's comparison to base R.

The first argument is always data, making it natural to use with the pipe operator (|>), enabling readable pipelines like in the mtcars example for fitting models across groups.

map() accepts functions, character vectors for name-based extraction, or numeric vectors for position-based extraction, offering versatile ways to apply operations without boilerplate code.

Built-in .progress argument for tracking long jobs and compatibility with in_parallel() for easy multi-core or distributed computing, as mentioned in the README's key features.