The unminified-webpack-plugin is a tool for webpack developers creating standalone libraries, automatically generating both minified and unminified JavaScript files in a single build process. It solves the common frustration of needing to run webpack twice to produce both versions of library files, offering configuration options for custom postfixes and file inclusion/exclusion patterns. The plugin is particularly useful for library authors who need to distribute both production-ready minified code and readable unminified versions for debugging or development purposes.