OpenDaylight

OpenDaylight is an open-source software-defined networking (SDN) controller platform. It is a collaborative project under the Linux Foundation's LF Networking, designed to provide a common, pluggable platform for building and operating software-defined networks.

The project originated in the early 2010s as a consortium of networking vendors and research institutions seeking to accelerate SDN adoption by creating a shared controller platform. It is released under the Apache License 2.0 and is freely available for use and modification.

Architecture and design: OpenDaylight uses a modular, service-oriented architecture built around the Model-Driven Service Abstraction Layer (MD-SAL), which separates application logic from protocol and data access. It runs atop an OSGi-based runtime (Karaf) and provides a set of southbound protocols (including OpenFlow and NETCONF) as well as northbound interfaces via REST APIs and YANG-based data models for applications.

Applications and ecosystem: OpenDaylight supports a growing set of applications that extend the controller's capabilities, enable network virtualization, and integrate with virtualized infrastructure, hardware devices, and NFV environments. It is used in academic research, enterprise networks, and service-provider deployments, with a broad ecosystem of contributors and users.

Licensing and governance: The project is hosted by the Linux Foundation's LF Networking and released under the Apache License 2.0, reflecting an emphasis on openness, interoperability, and collaborative development in software-defined networking. OpenDaylight continues to serve as a general-purpose platform for developing programmable networks across data centers, campuses, and carrier networks.