1.2. Getting to know Liferay

Liferay Portal is an open source project that uses the Lesser General Public License (LGPL). This is the GPL license you know and love, with one important exception: Liferay can be linked to software that isn’t open source. As long as you use Liferay’s extension points for your custom code, you don’t have to release your code as open source if you don’t wish to. You can keep it, sell it, or do whatever you want with it; it’s yours. But if you make a change to Liferay itself by modifying Liferay’s source code and want to redistribute the product thereafter, then you need to contribute that change back to Liferay. You get an important exception with the LGPL: you can use Liferay as a base for your own product and either open-source the result or sell it commercially if you wish. Or, if you want to change Liferay directly, you can contribute to the open source project. It’s entirely up to you.

You can download the open source version of Liferay Portal for free from Liferay’s web site.