The core of ROS is licensed under the standard three-clause BSD license. This is a very permissive open license that allows for reuse in commercial and closed source products. You can find more about the BSD license from the Opensource.org [BSD 3-Clause](http://opensource.org/licenses/BSD-3-Clause) page and Wikipedia's [BSD Licenses](http://en.wikipedia.org/wiki/BSD_licenses) entry.

While the core parts of ROS are licensed under the BSD license, other licenses are commonly used in the community packages, such as the [Apache 2.0](http://opensource.org/licenses/Apache-2.0) license, the [GPL](http://opensource.org/licenses/gpl-license) license, the [MIT](http://opensource.org/licenses/MIT) license, and even proprietary licenses. Each package in the ROS ecosystem is required to specify a license, so that it is easy for you to quickly identify if a package will meet your licensing needs.