This document discusses various ways to customize Alfresco using JavaScript APIs. It provides examples of extensions that improve default functionality, including adding document status tracking, public URL expiration dates, custom search filters, and a URL shortener. The examples are intended to demonstrate how to modify content models, forms, actions, behaviors, jobs, indicators, and templates using JavaScript. Links to the open-source code repositories are provided so others can use, modify, and learn from these types of Alfresco customizations.