Here are some special open source communities: 1. Drupal: Drupal is an open source platform for building and content management systems. It has strong expansibility and customization ability, and is suitable for building highly specialized. 2.Moodle: Moodle is an open source software used to create an online learning and education platform. It can help educational institutions, enterprises and government agencies to establish their own online learning courses and e-learning management systems. 3.OpenCart: OpenCart is an open source platform for establishing e-commerce. It provides many functions that are easy to use and customize, including multi-currency support, multiple support, and support for multiple payment methods. 4.inkscape: inkscape is an open source vector graphics editing software, which can be used to create icons, illustrations, logos and artworks. It has strong expansibility, and its functions can be enhanced by using plug-ins. 5.WordPress: WordPress is a popular open source blog and content management system, which is used to create and write blogs. It provides many customizable functions and templates to help users quickly create their own functions and templates.