Isotope may be used in commercial projects and applications with the one-time purchase of a commercial license. If you are paid to do your job, and part of your job is implementing Isotope, a commercial license is required.
### Commerical license
If you want to use Isotope to develop commercial sites, themes, projects, and applications, the Commercial license is the appropriate license. With this option, your source code is kept proprietary. Purchase a Isotope Commercial License at [isotope.metafizzy.co](http://isotope.metafizzy.co/#commerical-license)
### Open source license
http://isotope.metafizzy.co/license.html
If you are creating an open source application under a license compatible with the [GNU GPL license v3](https://www.gnu.org/licenses/gpl-3.0.html), you may use Isotope under the terms of the GPLv3.
For non-commercial, personal, or open source projects and applications, you may use Isotope under the terms of the [GPL v3 License](http://choosealicense.com/licenses/gpl-v3/). You may use Isotope for free.
[Read more about Isotope's license](http://isotope.metafizzy.co/license.html).