devtools

devtools is an R package that simplifies the workflow of developing R packages by providing functions for common tasks like loading code, generating documentation, running tests, and building packages.

The package streamlines iterative development through functions like load_all() for instantly testing changes without reinstalling, document() for updating documentation, and check() for validating package structure. It also provides installation helpers for packages from GitHub, GitLab, and other sources. devtools has been modularized into focused packages (like testthat, roxygen2, and usethis) that it automatically loads, giving developers a comprehensive toolkit through a single library call.