Version Details and Security Vulnerabilities

Autoprefixer is a valuable tool for web developers, automatically adding vendor prefixes to CSS rules, ensuring cross-browser compatibility based on the 'Can I Use' database. Comparing version 0.4.20130515 and 0.4.20130521, the primary difference lies in their release dates, with the latter being released approximately six days later. While the core functionality, description, dependencies (rework), and development dependencies (mocha, sinon, should, component, js-beautify, coffee-script) remain consistent, the newer version likely incorporates updated browser support data or bug fixes implemented during that period.

For developers, this means upgrading to the newer version could potentially resolve compatibility issues with newly released browser versions or address existing bugs. Package metadata such as the license (LGPL 3), repository URL, and author information remain consistent across both versions. Specifically, the packages are maintained by Andrey Sitnik, and the source code can be found via Github. Both versions rely on rework as a primary dependency for CSS parsing and manipulation. Therefore, for developers seeking the most up-to-date prefixing rules and improved stability, version 0.4.20130521 is the subtly advantageous choice, offering potentially improved cross-browser compatibility thanks to its more recent release date. Developers can easily install either version using npm.