WebSphere Liberty is a lightweight, flexible application server developed by IBM. It is designed to support modern cloud-native applications and microservices, allowing developers to build, deploy, and manage applications efficiently. With its modular architecture, users can easily customize the server by adding only the features they need, which helps optimize performance and resource usage. One of the key benefits of WebSphere Liberty is its fast startup time and low memory footprint, making it suitable for dynamic environments like Docker and Kubernetes. It supports various programming models, including Java EE and MicroProfile, enabling developers to leverage familiar tools and frameworks while building scalable applications.