single-spa is a microfrontend orchestration framework designed to compose multiple independent frontend applications into a single interface. It functions as a frontend routing engine and lazy-loading application loader that mounts and unmounts microfrontends based on the current URL without requiring a browser refresh.
The framework enables multi-framework frontend integration, allowing different JavaScript frameworks to coexist on one page. This architecture supports distributed frontend development, where separate teams develop and deploy modules independently while maintaining a unified user experience.
The system manages the lifecycle of these applications through a centralized registry and dynamic module loading. It optimizes frontend performance by deferring the download of application code until a specific route is accessed.