Open-sourcing is the act of processing source code of a proprietary software product and preparing to release it under an open source license.

Several notable applications have been through this process, including:

The task for large applications usually entails more than simply including a LICENSE file in the distribution and releasing it. Many proprietary applications will have a large amount of third party licensed code that will need to be stripped out or permission obtained for its release. Once the process has been completed, the application can be described as being open source or open-sourced.

See also: free software