Drone.io is an open-source Continuous Delivery (CD) platform that helps developers automate their software release cycle by enabling them to create, test and deploy applications quickly and easily. The platform provides a web interface that allows developers to easily configure their projects and the CD pipelines. Drone enables developers to create their own workflows and add custom plugins and integrations to their CD pipelines. Additionally, Drone supports integration with many popular source code repositories, such as GitHub and Bitbucket. With its powerful features, Drone allows developers to automate their software development process and quickly deliver high-quality applications to their customers. Drone also provides detailed reports and notifications to let developers easily monitor their CD pipelines and track the progress of their applications.
Discontinued Hudson is now Jenkins
Discontinued As noted on the official site, it is now retired.
Discontinued Source repositories have seen no activity since 2016.
The application is developing all the time. Buddy has a lot of integration and amazing support. Drone.io is no longer maintained: (I think Buddy is an excellent alternative for that).