The document outlines the new features and enhancements in Dolibarr version 21, including improved PHP compatibility, security updates, and a revamped user interface. Key changes involve significant reductions in technical debt, the introduction of new field formats, and enhancements in look and feel, such as improved tooltips and popup notifications. Additionally, new modules and APIs have been introduced, along with a dedicated merge process for maintenance, encouraging contributions from third-party developers.