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re-motion is dually licensed. You can have a commercial license for re-motion (includes support and more). This usually costs money, because it involves support or project work. There is a wikipedia article on the subject.
However, all of re-motion is also available under common variants of the GPL wikipedia. The GPL itself is not used in re-motion at the time of this writing; most of it is covered by a more consumer-friendly, less-strings-attached license.
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The LGPL is a fairly liberal license. You are allowed to link to the code, use the code and distribute it along with your own code. Only distributing modifications to the code requires you to distribute the modified code basis.
The following re-motion components are licensed under the LGPL. (Or,
actually, dually licensed. The LGPL is one of two options here.)
Other parts of re-motion are covered by the Affero GNU public license (AGPL). This license is like the GPL, with an important difference: providing running instances of AGPLed software over a network is treated like "distribution" (in contrast to the GPL, where it is not).
The security module re-strict is licensed under the AGPL. (Or, actually, dually licensed. The AGPL is one of two options here.)
The consequence: if you provide modified AGPLed software as a web service (for example) you must share your modifications. (wikipedia.)
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