Guice is an open-source dependency injection framework developed by Google, designed for Java applications. It simplifies the process of managing dependencies by allowing developers to define them programmatically without resorting to complex XML configuration files. Guice promotes modularity and testability by enabling clean separation of concerns and enhancing the flexibility of application design. It supports features such as type-safe configurations, lifecycle management, and integration with popular frameworks. Guice is widely used for building scalable and maintainable Java applications.